1640684745 has 24 divisors (see below), whose sum is σ = 3250118976. Its totient is φ = 750027168.

The previous prime is 1640684711. The next prime is 1640684779. The reversal of 1640684745 is 5474860461.

1640684745 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1640684711) and next prime (1640684779).

It is not a de Polignac number, because 1640684745 - 2⁶ = 1640684681 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1640684745.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2603947 + ... + 2604576.

It is an arithmetic number, because the mean of its divisors is an integer number (135421624).

Almost surely, 2^1640684745 is an apocalyptic number.

1640684745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640684745 is a deficient number, since it is larger than the sum of its proper divisors (1609434231).

1640684745 is a wasteful number, since it uses less digits than its factorization.

1640684745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5208541 (or 5208538 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The square root of 1640684745 is about 40505.3668666265. The cubic root of 1640684745 is about 1179.4378115340.

The spelling of 1640684745 in words is "one billion, six hundred forty million, six hundred eighty-four thousand, seven hundred forty-five".