21662537690 has 32 divisors (see below), whose sum is σ = 39477957120. Its totient is φ = 8557233984.

The previous prime is 21662537651. The next prime is 21662537717. The reversal of 21662537690 is 9673526612.

It is a super-2 number, since 2×21662537690² (a number of 21 digits) contains 22 as substring.

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, 3688076 + ... + 3693944.

It is an arithmetic number, because the mean of its divisors is an integer number (1233686160).

Almost surely, 2^21662537690 is an apocalyptic number.

21662537690 is a deficient number, since it is larger than the sum of its proper divisors (17815419430).

21662537690 is a wasteful number, since it uses less digits than its factorization.

21662537690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10406.

The product of its (nonzero) digits is 816480, while the sum is 47.

The spelling of 21662537690 in words is "twenty-one billion, six hundred sixty-two million, five hundred thirty-seven thousand, six hundred ninety".