121557707502 has 128 divisors (see below), whose sum is σ = 313043927040. Its totient is φ = 30547704960.

The previous prime is 121557707497. The next prime is 121557707549. The reversal of 121557707502 is 205707755121.

121557707502 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3039963 + ... + 3079689.

It is an arithmetic number, because the mean of its divisors is an integer number (2445655680).

Almost surely, 2^121557707502 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121557707502, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156521963520).

121557707502 is an abundant number, since it is smaller than the sum of its proper divisors (191486219538).

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

121557707502 is a wasteful number, since it uses less digits than its factorization.

121557707502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39966.

The product of its (nonzero) digits is 171500, while the sum is 42.

The spelling of 121557707502 in words is "one hundred twenty-one billion, five hundred fifty-seven million, seven hundred seven thousand, five hundred two".