21218679755 has 16 divisors (see below), whose sum is σ = 31338358464. Its totient is φ = 13430724480.

The previous prime is 21218679733. The next prime is 21218679763. The reversal of 21218679755 is 55797681212.

It is not a de Polignac number, because 21218679755 - 2¹⁰ = 21218678731 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21218679697 and 21218679706.

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, 23316776 + ... + 23317685.

It is an arithmetic number, because the mean of its divisors is an integer number (1958647404).

Almost surely, 2^21218679755 is an apocalyptic number.

21218679755 is a deficient number, since it is larger than the sum of its proper divisors (10119678709).

21218679755 is a wasteful number, since it uses less digits than its factorization.

21218679755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46634486.

The product of its digits is 2116800, while the sum is 53.

The spelling of 21218679755 in words is "twenty-one billion, two hundred eighteen million, six hundred seventy-nine thousand, seven hundred fifty-five".