20571523321575 has 12 divisors (see below), whose sum is σ = 34011585225128. Its totient is φ = 10971479104800.

The previous prime is 20571523321549. The next prime is 20571523321621. The reversal of 20571523321575 is 57512332517502.

It is a happy number.

It is not a de Polignac number, because 20571523321575 - 2¹⁸ = 20571523059431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 137143488736 + ... + 137143488885.

Almost surely, 2^{20571523321575} is an apocalyptic number.

20571523321575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20571523321575 is a deficient number, since it is larger than the sum of its proper divisors (13440061903553).

20571523321575 is a wasteful number, since it uses less digits than its factorization.

20571523321575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274286977634 (or 274286977629 counting only the distinct ones).

The product of its (nonzero) digits is 2205000, while the sum is 48.

The spelling of 20571523321575 in words is "twenty trillion, five hundred seventy-one billion, five hundred twenty-three million, three hundred twenty-one thousand, five hundred seventy-five".