1640453745 has 16 divisors (see below), whose sum is σ = 2999687040. Its totient is φ = 749921664.

The previous prime is 1640453677. The next prime is 1640453767. The reversal of 1640453745 is 5473540461.

It is a happy number.

It is not a de Polignac number, because 1640453745 - 2⁸ = 1640453489 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7811580 + ... + 7811789.

It is an arithmetic number, because the mean of its divisors is an integer number (187480440).

Almost surely, 2^1640453745 is an apocalyptic number.

1640453745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640453745 is a deficient number, since it is larger than the sum of its proper divisors (1359233295).

1640453745 is a wasteful number, since it uses less digits than its factorization.

1640453745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15623384.

The product of its (nonzero) digits is 201600, while the sum is 39.

The square root of 1640453745 is about 40502.5152922630. The cubic root of 1640453745 is about 1179.3824560038.

The spelling of 1640453745 in words is "one billion, six hundred forty million, four hundred fifty-three thousand, seven hundred forty-five".