64195235990639 has 4 divisors (see below), whose sum is σ = 69133331066856. Its totient is φ = 59257140914424.

The previous prime is 64195235990623. The next prime is 64195235990651. The reversal of 64195235990639 is 93609953259146.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64195235990639 - 2⁴ = 64195235990623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64195235290639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2469047538089 + ... + 2469047538114.

It is an arithmetic number, because the mean of its divisors is an integer number (17283332766714).

Almost surely, 2^{64195235990639} is an apocalyptic number.

64195235990639 is a deficient number, since it is larger than the sum of its proper divisors (4938095076217).

64195235990639 is a wasteful number, since it uses less digits than its factorization.

64195235990639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4938095076216.

The product of its (nonzero) digits is 425152800, while the sum is 71.

The spelling of 64195235990639 in words is "sixty-four trillion, one hundred ninety-five billion, two hundred thirty-five million, nine hundred ninety thousand, six hundred thirty-nine".