64400740 has 12 divisors (see below), whose sum is σ = 135241596. Its totient is φ = 25760288.

The previous prime is 64400729. The next prime is 64400761. The reversal of 64400740 is 4700446.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19027044 + 45373696 = 4362^2 + 6736^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1609999 + ... + 1610038.

It is an arithmetic number, because the mean of its divisors is an integer number (11270133).

Almost surely, 2^64400740 is an apocalyptic number.

It is an amenable number.

64400740 is an abundant number, since it is smaller than the sum of its proper divisors (70840856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64400740 is a wasteful number, since it uses less digits than its factorization.

64400740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3220046 (or 3220044 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 64400740 is about 8025.0071651058. The cubic root of 64400740 is about 400.8331384958.

The spelling of 64400740 in words is "sixty-four million, four hundred thousand, seven hundred forty".