1613645640 has 48 divisors (see below), whose sum is σ = 5244349500. Its totient is φ = 430305408.

The previous prime is 1613645633. The next prime is 1613645641. The reversal of 1613645640 is 465463161.

It is a happy number.

1613645640 is a `hidden beast` number, since 1 + 6 + 1 + 3 + 6 + 4 + 5 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1539306756 + 74338884 = 39234^2 + 8622^2 .

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 = 1613645595 and 1613645604.

It is not an unprimeable number, because it can be changed into a prime (1613645641) 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, 2240815 + ... + 2241534.

Almost surely, 2^1613645640 is an apocalyptic number.

1613645640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1613645640 is an abundant number, since it is smaller than the sum of its proper divisors (3630703860).

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

1613645640 is a wasteful number, since it uses less digits than its factorization.

1613645640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4482366 (or 4482359 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 1613645640 is about 40170.2083639107. The cubic root of 1613645640 is about 1172.9226951320.

It can be divided in two parts, 16136 and 45640, that added together give a triangular number (61776 = T₃₅₁).

The spelling of 1613645640 in words is "one billion, six hundred thirteen million, six hundred forty-five thousand, six hundred forty".