21089357709 has 32 divisors (see below), whose sum is σ = 32319344640. Its totient is φ = 11982572352.

The previous prime is 21089357659. The next prime is 21089357741. The reversal of 21089357709 is 90775398012.

It is not a de Polignac number, because 21089357709 - 2⁹ = 21089357197 is a prime.

It is a super-2 number, since 2×21089357709² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21089357789) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2714172 + ... + 2721930.

It is an arithmetic number, because the mean of its divisors is an integer number (1009979520).

Almost surely, 2^21089357709 is an apocalyptic number.

It is an amenable number.

21089357709 is a deficient number, since it is larger than the sum of its proper divisors (11229986931).

21089357709 is a wasteful number, since it uses less digits than its factorization.

21089357709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8489.

The product of its (nonzero) digits is 952560, while the sum is 51.

The spelling of 21089357709 in words is "twenty-one billion, eighty-nine million, three hundred fifty-seven thousand, seven hundred nine".