64720213531 has 2 divisors, whose sum is σ = 64720213532. Its totient is φ = 64720213530.

The previous prime is 64720213517. The next prime is 64720213541. The reversal of 64720213531 is 13531202746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64720213531 - 2²⁵ = 64686659099 is a prime.

It is a super-2 number, since 2×64720213531² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64720213541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32360106765 + 32360106766.

It is an arithmetic number, because the mean of its divisors is an integer number (32360106766).

Almost surely, 2^64720213531 is an apocalyptic number.

64720213531 is a deficient number, since it is larger than the sum of its proper divisors (1).

64720213531 is an equidigital number, since it uses as much as digits as its factorization.

64720213531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 34.

The spelling of 64720213531 in words is "sixty-four billion, seven hundred twenty million, two hundred thirteen thousand, five hundred thirty-one".