21910471684 has 6 divisors (see below), whose sum is σ = 38343325454. Its totient is φ = 10955235840.

The previous prime is 21910471657. The next prime is 21910471717. The reversal of 21910471684 is 48617401912.

It can be written as a sum of positive squares in only one way, i.e., 19732382784 + 2178088900 = 140472^2 + 46670^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21910471684.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2738808957 + ... + 2738808964.

Almost surely, 2^21910471684 is an apocalyptic number.

It is an amenable number.

21910471684 is a deficient number, since it is larger than the sum of its proper divisors (16432853770).

21910471684 is a wasteful number, since it uses less digits than its factorization.

21910471684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5477617925 (or 5477617923 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 43.

The spelling of 21910471684 in words is "twenty-one billion, nine hundred ten million, four hundred seventy-one thousand, six hundred eighty-four".