640254744 has 24 divisors (see below), whose sum is σ = 1734023460. Its totient is φ = 213418224.

The previous prime is 640254707. The next prime is 640254751. The reversal of 640254744 is 447452046.

640254744 is a `hidden beast` number, since 640 + 2 + 5 + 4 + 7 + 4 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×640254744² = 819852274429011072, which contains 22 as substring.

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 = 640254699 and 640254708.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4446142 + ... + 4446285.

Almost surely, 2^640254744 is an apocalyptic number.

It is an amenable number.

640254744 is an abundant number, since it is smaller than the sum of its proper divisors (1093768716).

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

640254744 is a wasteful number, since it uses less digits than its factorization.

640254744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8892439 (or 8892432 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 36.

The square root of 640254744 is about 25303.2556008115. The cubic root of 640254744 is about 861.8882002854. Note that the first 3 decimals are identical.

The spelling of 640254744 in words is "six hundred forty million, two hundred fifty-four thousand, seven hundred forty-four".