64400007 has 16 divisors (see below), whose sum is σ = 98496512. Its totient is φ = 36663840.

The previous prime is 64399999. The next prime is 64400009. The reversal of 64400007 is 70000446.

It is not a de Polignac number, because 64400007 - 2³ = 64399999 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64400009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 282 + ... + 11352.

It is an arithmetic number, because the mean of its divisors is an integer number (6156032).

Almost surely, 2^64400007 is an apocalyptic number.

64400007 is a deficient number, since it is larger than the sum of its proper divisors (34096505).

64400007 is a wasteful number, since it uses less digits than its factorization.

64400007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11358.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 64400007 is about 8024.9614952347. The cubic root of 64400007 is about 400.8316177483.

The spelling of 64400007 in words is "sixty-four million, four hundred thousand, seven".