64145375621 has 2 divisors, whose sum is σ = 64145375622. Its totient is φ = 64145375620.

The previous prime is 64145375599. The next prime is 64145375639. The reversal of 64145375621 is 12657354146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61154817025 + 2990558596 = 247295^2 + 54686^2 .

It is a cyclic number.

It is not a de Polignac number, because 64145375621 - 2²⁶ = 64078266757 is a prime.

It is a super-2 number, since 2×64145375621² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64145375221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32072687810 + 32072687811.

It is an arithmetic number, because the mean of its divisors is an integer number (32072687811).

Almost surely, 2^64145375621 is an apocalyptic number.

It is an amenable number.

64145375621 is a deficient number, since it is larger than the sum of its proper divisors (1).

64145375621 is an equidigital number, since it uses as much as digits as its factorization.

64145375621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 604800, while the sum is 44.

The spelling of 64145375621 in words is "sixty-four billion, one hundred forty-five million, three hundred seventy-five thousand, six hundred twenty-one".