64731565537 has 2 divisors, whose sum is σ = 64731565538. Its totient is φ = 64731565536.

The previous prime is 64731565471. The next prime is 64731565543. The reversal of 64731565537 is 73556513746.

It is a happy number.

64731565537 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64098086976 + 633478561 = 253176^2 + 25169^2 .

It is a cyclic number.

It is not a de Polignac number, because 64731565537 - 2²³ = 64723176929 is a prime.

It is not a weakly prime, because it can be changed into another prime (64731565597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32365782768 + 32365782769.

It is an arithmetic number, because the mean of its divisors is an integer number (32365782769).

Almost surely, 2^64731565537 is an apocalyptic number.

It is an amenable number.

64731565537 is a deficient number, since it is larger than the sum of its proper divisors (1).

64731565537 is an equidigital number, since it uses as much as digits as its factorization.

64731565537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7938000, while the sum is 52.

The spelling of 64731565537 in words is "sixty-four billion, seven hundred thirty-one million, five hundred sixty-five thousand, five hundred thirty-seven".