64637623 has 4 divisors (see below), whose sum is σ = 64779520. Its totient is φ = 64495728.

The previous prime is 64637603. The next prime is 64637633. The reversal of 64637623 is 32673646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32673646 = 2 ⋅16336823.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64637623 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 (64637603) 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, 70263 + ... + 71176.

It is an arithmetic number, because the mean of its divisors is an integer number (16194880).

Almost surely, 2^64637623 is an apocalyptic number.

64637623 is a deficient number, since it is larger than the sum of its proper divisors (141897).

64637623 is a wasteful number, since it uses less digits than its factorization.

64637623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141896.

The product of its digits is 108864, while the sum is 37.

The square root of 64637623 is about 8039.7526703251. The cubic root of 64637623 is about 401.3239940144.

The spelling of 64637623 in words is "sixty-four million, six hundred thirty-seven thousand, six hundred twenty-three".