640696230720 has 672 divisors, whose sum is σ = 2767688851200. Its totient is φ = 135177154560.

The previous prime is 640696230719. The next prime is 640696230721. The reversal of 640696230720 is 27032696046.

640696230720 is a `hidden beast` number, since 6 + 406 + 9 + 6 + 230 + 7 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (640696230719) and next prime (640696230721).

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640696230721) 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, 12816975 + ... + 12866865.

It is an arithmetic number, because the mean of its divisors is an integer number (4118584600).

Almost surely, 2^640696230720 is an apocalyptic number.

640696230720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640696230720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1383844425600).

640696230720 is an abundant number, since it is smaller than the sum of its proper divisors (2126992620480).

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

640696230720 is a wasteful number, since it uses less digits than its factorization.

640696230720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49948 (or 49921 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 45.

The spelling of 640696230720 in words is "six hundred forty billion, six hundred ninety-six million, two hundred thirty thousand, seven hundred twenty".