21123977716 has 24 divisors (see below), whose sum is σ = 38319160320. Its totient is φ = 10178498400.

The previous prime is 21123977687. The next prime is 21123977761. The reversal of 21123977716 is 61777932112.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 326755 + ... + 386026.

It is an arithmetic number, because the mean of its divisors is an integer number (1596631680).

Almost surely, 2^21123977716 is an apocalyptic number.

It is an amenable number.

21123977716 is a deficient number, since it is larger than the sum of its proper divisors (17195182604).

21123977716 is a wasteful number, since it uses less digits than its factorization.

21123977716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713055 (or 713053 counting only the distinct ones).

The product of its digits is 222264, while the sum is 46.

The spelling of 21123977716 in words is "twenty-one billion, one hundred twenty-three million, nine hundred seventy-seven thousand, seven hundred sixteen".