21031768771 has 16 divisors (see below), whose sum is σ = 23429173600. Its totient is φ = 18753285888.

The previous prime is 21031768717. The next prime is 21031768837. The reversal of 21031768771 is 17786713012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21031768771 - 2²⁵ = 20998214339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21031768871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90426 + ... + 224143.

It is an arithmetic number, because the mean of its divisors is an integer number (1464323350).

Almost surely, 2^21031768771 is an apocalyptic number.

21031768771 is a deficient number, since it is larger than the sum of its proper divisors (2397404829).

21031768771 is a wasteful number, since it uses less digits than its factorization.

21031768771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314758.

The product of its (nonzero) digits is 98784, while the sum is 43.

The spelling of 21031768771 in words is "twenty-one billion, thirty-one million, seven hundred sixty-eight thousand, seven hundred seventy-one".