21879911697 has 16 divisors (see below), whose sum is σ = 33887390592. Its totient is φ = 12297841920.

The previous prime is 21879911687. The next prime is 21879911747. The reversal of 21879911697 is 79611997812.

It is not a de Polignac number, because 21879911697 - 2¹⁴ = 21879895313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21879911697.

It is not an unprimeable number, because it can be changed into a prime (21879911687) 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, 8538888 + ... + 8541449.

It is an arithmetic number, because the mean of its divisors is an integer number (2117961912).

Almost surely, 2^21879911697 is an apocalyptic number.

It is an amenable number.

21879911697 is a deficient number, since it is larger than the sum of its proper divisors (12007478895).

21879911697 is a wasteful number, since it uses less digits than its factorization.

21879911697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17080408.

The product of its digits is 3429216, while the sum is 60.

The spelling of 21879911697 in words is "twenty-one billion, eight hundred seventy-nine million, nine hundred eleven thousand, six hundred ninety-seven".