616643640 has 48 divisors (see below), whose sum is σ = 2004093000. Its totient is φ = 164438208.

The previous prime is 616643623. The next prime is 616643641. The reversal of 616643640 is 46346616.

616643640 is a `hidden beast` number, since 6 + 1 + 6 + 6 + 4 + 3 + 640 = 666.

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 = 616643595 and 616643604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (616643641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 856090 + ... + 856809.

Almost surely, 2^616643640 is an apocalyptic number.

616643640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

616643640 is an abundant number, since it is smaller than the sum of its proper divisors (1387449360).

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

616643640 is a wasteful number, since it uses less digits than its factorization.

616643640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1712916 (or 1712909 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 616643640 is about 24832.3104039878. The cubic root of 616643640 is about 851.1604173876.

The spelling of 616643640 in words is "six hundred sixteen million, six hundred forty-three thousand, six hundred forty".