21663662570 has 32 divisors (see below), whose sum is σ = 42864313536. Its totient is φ = 7817555200.

The previous prime is 21663662561. The next prime is 21663662593. The reversal of 21663662570 is 7526636612.

It is a happy number.

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, 737279 + ... + 766098.

It is an arithmetic number, because the mean of its divisors is an integer number (1339509798).

Almost surely, 2^21663662570 is an apocalyptic number.

21663662570 is a deficient number, since it is larger than the sum of its proper divisors (21200650966).

21663662570 is a wasteful number, since it uses less digits than its factorization.

21663662570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1503526.

The product of its (nonzero) digits is 544320, while the sum is 44.

The spelling of 21663662570 in words is "twenty-one billion, six hundred sixty-three million, six hundred sixty-two thousand, five hundred seventy".