64636879 has 4 divisors (see below), whose sum is σ = 68038840. Its totient is φ = 61234920.

The previous prime is 64636867. The next prime is 64636921. The reversal of 64636879 is 97863646.

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 64636879 - 2¹¹ = 64634831 is a prime.

It is a super-2 number, since 2×64636879² = 8355852253721282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64636079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1700952 + ... + 1700989.

It is an arithmetic number, because the mean of its divisors is an integer number (17009710).

Almost surely, 2^64636879 is an apocalyptic number.

64636879 is a deficient number, since it is larger than the sum of its proper divisors (3401961).

64636879 is a wasteful number, since it uses less digits than its factorization.

64636879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3401960.

The product of its digits is 1306368, while the sum is 49.

The square root of 64636879 is about 8039.7064001119. The cubic root of 64636879 is about 401.3224542187.

The spelling of 64636879 in words is "sixty-four million, six hundred thirty-six thousand, eight hundred seventy-nine".