921978120311 has 4 divisors (see below), whose sum is σ = 922420742712. Its totient is φ = 921535497912.

The previous prime is 921978120299. The next prime is 921978120331. The reversal of 921978120311 is 113021879129.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 921978120311 - 2³⁴ = 904798251127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921978120331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221308076 + ... + 221312241.

It is an arithmetic number, because the mean of its divisors is an integer number (230605185678).

Almost surely, 2^921978120311 is an apocalyptic number.

921978120311 is a deficient number, since it is larger than the sum of its proper divisors (442622401).

921978120311 is a wasteful number, since it uses less digits than its factorization.

921978120311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442622400.

The product of its (nonzero) digits is 54432, while the sum is 44.

The spelling of 921978120311 in words is "nine hundred twenty-one billion, nine hundred seventy-eight million, one hundred twenty thousand, three hundred eleven".