21667418408 has 32 divisors (see below), whose sum is σ = 43039670760. Its totient is φ = 10190868480.

The previous prime is 21667418407. The next prime is 21667418413. The reversal of 21667418408 is 80481476612.

It can be written as a sum of positive squares in 4 ways, for example, as 20129366884 + 1538051524 = 141878^2 + 39218^2 .

It is not an unprimeable number, because it can be changed into a prime (21667418407) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212198 + ... + 297258.

Almost surely, 2^21667418408 is an apocalyptic number.

It is an amenable number.

21667418408 is a deficient number, since it is larger than the sum of its proper divisors (21372252352).

21667418408 is a wasteful number, since it uses less digits than its factorization.

21667418408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86957 (or 86953 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 47.

The spelling of 21667418408 in words is "twenty-one billion, six hundred sixty-seven million, four hundred eighteen thousand, four hundred eight".