640453653 has 96 divisors (see below), whose sum is σ = 1190492160. Its totient is φ = 323326080.

The previous prime is 640453637. The next prime is 640453657. The reversal of 640453653 is 356354046.

640453653 is a `hidden beast` number, since 640 + 4 + 5 + 3 + 6 + 5 + 3 = 666.

It is not a de Polignac number, because 640453653 - 2⁴ = 640453637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640453657) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1183563 + ... + 1184103.

It is an arithmetic number, because the mean of its divisors is an integer number (12400960).

Almost surely, 2^640453653 is an apocalyptic number.

640453653 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

640453653 is a deficient number, since it is larger than the sum of its proper divisors (550038507).

640453653 is a wasteful number, since it uses less digits than its factorization.

640453653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639 (or 636 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

The square root of 640453653 is about 25307.1857977137. The cubic root of 640453653 is about 861.9774457881.

The spelling of 640453653 in words is "six hundred forty million, four hundred fifty-three thousand, six hundred fifty-three".