15121864890 has 240 divisors, whose sum is σ = 44935389576. Its totient is φ = 3646114560.

The previous prime is 15121864867. The next prime is 15121864897. The reversal of 15121864890 is 9846812151.

It is a happy number.

15121864890 is a `hidden beast` number, since 1 + 512 + 1 + 8 + 6 + 48 + 90 = 666.

15121864890 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6070435569 + 9051429321 = 77913^2 + 95139^2 .

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (15121864897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 27148492 + ... + 27149048.

Almost surely, 2^15121864890 is an apocalyptic number.

15121864890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 15121864890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22467694788).

15121864890 is an abundant number, since it is smaller than the sum of its proper divisors (29813524686).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15121864890 is a wasteful number, since it uses less digits than its factorization.

15121864890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875 (or 855 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The spelling of 15121864890 in words is "fifteen billion, one hundred twenty-one million, eight hundred sixty-four thousand, eight hundred ninety".