64542944639 has 2 divisors, whose sum is σ = 64542944640. Its totient is φ = 64542944638.

The previous prime is 64542944629. The next prime is 64542944657. The reversal of 64542944639 is 93644924546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64542944639 - 2⁴ = 64542944623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64542944629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32271472319 + 32271472320.

It is an arithmetic number, because the mean of its divisors is an integer number (32271472320).

Almost surely, 2^64542944639 is an apocalyptic number.

64542944639 is a deficient number, since it is larger than the sum of its proper divisors (1).

64542944639 is an equidigital number, since it uses as much as digits as its factorization.

64542944639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22394880, while the sum is 56.

The spelling of 64542944639 in words is "sixty-four billion, five hundred forty-two million, nine hundred forty-four thousand, six hundred thirty-nine".