6439564694 has 4 divisors (see below), whose sum is σ = 9659347044. Its totient is φ = 3219782346.

The previous prime is 6439564669. The next prime is 6439564709. The reversal of 6439564694 is 4964659346.

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

It is a super-2 number, since 2×6439564694² = 82935986896422627272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1609891172 + ... + 1609891175.

It is an arithmetic number, because the mean of its divisors is an integer number (2414836761).

Almost surely, 2^6439564694 is an apocalyptic number.

6439564694 is a deficient number, since it is larger than the sum of its proper divisors (3219782350).

6439564694 is a wasteful number, since it uses less digits than its factorization.

6439564694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3219782349.

The product of its digits is 16796160, while the sum is 56.

The square root of 6439564694 is about 80246.8983450451. The cubic root of 6439564694 is about 1860.4535732397.

The spelling of 6439564694 in words is "six billion, four hundred thirty-nine million, five hundred sixty-four thousand, six hundred ninety-four".