74564640 has 144 divisors (see below), whose sum is σ = 259518168. Its totient is φ = 19488768.

The previous prime is 74564617. The next prime is 74564671. The reversal of 74564640 is 4646547.

74564640 is a `hidden beast` number, since 7 + 4 + 5 + 6 + 4 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 74028816 + 535824 = 8604^2 + 732^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 74564595 and 74564604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75832 + ... + 76808.

Almost surely, 2^74564640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 74564640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129759084).

74564640 is an abundant number, since it is smaller than the sum of its proper divisors (184953528).

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

74564640 is a wasteful number, since it uses less digits than its factorization.

74564640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051 (or 1040 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The square root of 74564640 is about 8635.0819336009. The cubic root of 74564640 is about 420.8987556580.

The spelling of 74564640 in words is "seventy-four million, five hundred sixty-four thousand, six hundred forty".