64400669 has 4 divisors (see below), whose sum is σ = 65770944. Its totient is φ = 63030396.

The previous prime is 64400663. The next prime is 64400717. The reversal of 64400669 is 96600446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64400669 is a prime.

It is a super-2 number, since 2×64400669² = 8294892335295122, 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 (64400663) 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, 685067 + ... + 685160.

It is an arithmetic number, because the mean of its divisors is an integer number (16442736).

Almost surely, 2^64400669 is an apocalyptic number.

It is an amenable number.

64400669 is a deficient number, since it is larger than the sum of its proper divisors (1370275).

64400669 is a wasteful number, since it uses less digits than its factorization.

64400669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1370274.

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 64400669 is about 8025.0027414326. The cubic root of 64400669 is about 400.8329911934.

The spelling of 64400669 in words is "sixty-four million, four hundred thousand, six hundred sixty-nine".