21336771965 has 16 divisors (see below), whose sum is σ = 25976681856. Its totient is φ = 16821268800.

The previous prime is 21336771949. The next prime is 21336771971. The reversal of 21336771965 is 56917763312.

It is not a de Polignac number, because 21336771965 - 2⁴ = 21336771949 is a prime.

It is a super-2 number, since 2×21336771965² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent 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, 832634 + ... + 857876.

It is an arithmetic number, because the mean of its divisors is an integer number (1623542616).

Almost surely, 2^21336771965 is an apocalyptic number.

It is an amenable number.

21336771965 is a deficient number, since it is larger than the sum of its proper divisors (4639909891).

21336771965 is a wasteful number, since it uses less digits than its factorization.

21336771965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27700.

The product of its digits is 1428840, while the sum is 50.

The spelling of 21336771965 in words is "twenty-one billion, three hundred thirty-six million, seven hundred seventy-one thousand, nine hundred sixty-five".