121251867840 has 336 divisors, whose sum is σ = 442572818688. Its totient is φ = 31581010944.

The previous prime is 121251867817. The next prime is 121251867853. The reversal of 121251867840 is 48768152121.

121251867840 is a `hidden beast` number, since 1 + 21 + 2 + 518 + 6 + 78 + 40 = 666.

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

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 3325549 + ... + 3361811.

It is an arithmetic number, because the mean of its divisors is an integer number (1317181008).

Almost surely, 2^121251867840 is an apocalyptic number.

121251867840 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 121251867840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221286409344).

121251867840 is an abundant number, since it is smaller than the sum of its proper divisors (321320950848).

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

121251867840 is an equidigital number, since it uses as much as digits as its factorization.

121251867840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36338 (or 36316 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 121251867840 in words is "one hundred twenty-one billion, two hundred fifty-one million, eight hundred sixty-seven thousand, eight hundred forty".