121509256128 has 112 divisors (see below), whose sum is σ = 361276855296. Its totient is φ = 35761904640.

The previous prime is 121509256109. The next prime is 121509256147. The reversal of 121509256128 is 821652905121.

It is an interprime number because it is at equal distance from previous prime (121509256109) and next prime (121509256147).

It is a self number, because there is not a number n which added to its sum of digits gives 121509256128.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1000888 + ... + 1115703.

It is an arithmetic number, because the mean of its divisors is an integer number (3225686208).

Almost surely, 2^121509256128 is an apocalyptic number.

It is an amenable number.

121509256128 is an abundant number, since it is smaller than the sum of its proper divisors (239767599168).

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

121509256128 is a wasteful number, since it uses less digits than its factorization.

121509256128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2116642 (or 2116632 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 42.

The spelling of 121509256128 in words is "one hundred twenty-one billion, five hundred nine million, two hundred fifty-six thousand, one hundred twenty-eight".