64400787 has 24 divisors (see below), whose sum is σ = 101994048. Its totient is φ = 38833200.

The previous prime is 64400783. The next prime is 64400789. The reversal of 64400787 is 78700446.

It is a happy number.

64400787 is a `hidden beast` number, since 644 + 0 + 0 + 7 + 8 + 7 = 666.

It is not a de Polignac number, because 64400787 - 2² = 64400783 is a prime.

It is a super-2 number, since 2×64400787² = 8294922732438738, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64400783) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19348 + ... + 22430.

It is an arithmetic number, because the mean of its divisors is an integer number (4249752).

Almost surely, 2^64400787 is an apocalyptic number.

64400787 is a deficient number, since it is larger than the sum of its proper divisors (37593261).

64400787 is a wasteful number, since it uses less digits than its factorization.

64400787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3311 (or 3308 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 64400787 is about 8025.0100934516. The cubic root of 64400787 is about 400.8332360059.

The spelling of 64400787 in words is "sixty-four million, four hundred thousand, seven hundred eighty-seven".