1640454645 has 64 divisors (see below), whose sum is σ = 2799857664. Its totient is φ = 818442240.

The previous prime is 1640454637. The next prime is 1640454689. The reversal of 1640454645 is 5464540461.

It is not a de Polignac number, because 1640454645 - 2³ = 1640454637 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4727362 + ... + 4727708.

It is an arithmetic number, because the mean of its divisors is an integer number (43747776).

Almost surely, 2^1640454645 is an apocalyptic number.

1640454645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640454645 is a deficient number, since it is larger than the sum of its proper divisors (1159403019).

1640454645 is a wasteful number, since it uses less digits than its factorization.

1640454645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642.

The product of its (nonzero) digits is 230400, while the sum is 39.

The square root of 1640454645 is about 40502.5264026826. The cubic root of 1640454645 is about 1179.3826716848.

The spelling of 1640454645 in words is "one billion, six hundred forty million, four hundred fifty-four thousand, six hundred forty-five".