21571585802428 has 24 divisors (see below), whose sum is σ = 38949412178880. Its totient is φ = 10448334361920.

The previous prime is 21571585802359. The next prime is 21571585802527. The reversal of 21571585802428 is 82420858517512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 643988083 + ... + 644021578.

It is an arithmetic number, because the mean of its divisors is an integer number (1622892174120).

Almost surely, 2^{21571585802428} is an apocalyptic number.

It is an amenable number.

21571585802428 is a deficient number, since it is larger than the sum of its proper divisors (17377826376452).

21571585802428 is a wasteful number, since it uses less digits than its factorization.

21571585802428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1288009797 (or 1288009795 counting only the distinct ones).

The product of its (nonzero) digits is 14336000, while the sum is 58.

The spelling of 21571585802428 in words is "twenty-one trillion, five hundred seventy-one billion, five hundred eighty-five million, eight hundred two thousand, four hundred twenty-eight".