121556664654 has 64 divisors (see below), whose sum is σ = 258681772800. Its totient is φ = 38013437952.

The previous prime is 121556664637. The next prime is 121556664737. The reversal of 121556664654 is 456466655121.

It is a junction number, because it is equal to n+sod(n) for n = 121556664597 and 121556664606.

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, 1401937 + ... + 1486115.

It is an arithmetic number, because the mean of its divisors is an integer number (4041902700).

Almost surely, 2^121556664654 is an apocalyptic number.

121556664654 is an abundant number, since it is smaller than the sum of its proper divisors (137125108146).

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

121556664654 is a wasteful number, since it uses less digits than its factorization.

121556664654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84449.

The product of its digits is 5184000, while the sum is 51.

The spelling of 121556664654 in words is "one hundred twenty-one billion, five hundred fifty-six million, six hundred sixty-four thousand, six hundred fifty-four".