15121021020 has 96 divisors (see below), whose sum is σ = 48491509248. Its totient is φ = 3448787712.

The previous prime is 15121020961. The next prime is 15121021037. The reversal of 15121021020 is 2012012151.

It is a super-4 number, since 4×15121021020⁴ (a number of 42 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 157594 + ... + 234686.

It is an arithmetic number, because the mean of its divisors is an integer number (505119888).

Almost surely, 2^15121021020 is an apocalyptic number.

15121021020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15121021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24245754624).

15121021020 is an abundant number, since it is smaller than the sum of its proper divisors (33370488228).

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

15121021020 is a wasteful number, since it uses less digits than its factorization.

15121021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77579 (or 77577 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 15.

Adding to 15121021020 its reverse (2012012151), we get a palindrome (17133033171).

The spelling of 15121021020 in words is "fifteen billion, one hundred twenty-one million, twenty-one thousand, twenty".