64699645 has 4 divisors (see below), whose sum is σ = 77639580. Its totient is φ = 51759712.

The previous prime is 64699639. The next prime is 64699669. The reversal of 64699645 is 54699646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54699646 = 2 ⋅27349823.

It can be written as a sum of positive squares in 2 ways, for example, as 25836889 + 38862756 = 5083^2 + 6234^2 .

It is a cyclic number.

It is not a de Polignac number, because 64699645 - 2¹³ = 64691453 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6469960 + ... + 6469969.

It is an arithmetic number, because the mean of its divisors is an integer number (19409895).

Almost surely, 2^64699645 is an apocalyptic number.

It is an amenable number.

64699645 is a deficient number, since it is larger than the sum of its proper divisors (12939935).

64699645 is a wasteful number, since it uses less digits than its factorization.

64699645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12939934.

The product of its digits is 1399680, while the sum is 49.

The square root of 64699645 is about 8043.6089536973. The cubic root of 64699645 is about 401.4523143260.

Subtracting from 64699645 its reverse (54699646), we obtain a palindrome (9999999).

The spelling of 64699645 in words is "sixty-four million, six hundred ninety-nine thousand, six hundred forty-five".