21337039581 has 32 divisors (see below), whose sum is σ = 33479816832. Its totient is φ = 11916533760.

The previous prime is 21337039571. The next prime is 21337039621. The reversal of 21337039581 is 18593073312.

It is not a de Polignac number, because 21337039581 - 2⁹ = 21337039069 is a prime.

It is a super-2 number, since 2×21337039581² (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 (21337039511) 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, 212461 + ... + 296333.

It is an arithmetic number, because the mean of its divisors is an integer number (1046244276).

Almost surely, 2^21337039581 is an apocalyptic number.

It is an amenable number.

21337039581 is a deficient number, since it is larger than the sum of its proper divisors (12142777251).

21337039581 is a wasteful number, since it uses less digits than its factorization.

21337039581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84493.

The product of its (nonzero) digits is 136080, while the sum is 42.

The spelling of 21337039581 in words is "twenty-one billion, three hundred thirty-seven million, thirty-nine thousand, five hundred eighty-one".