1643825457 has 12 divisors (see below), whose sum is σ = 2429634064. Its totient is φ = 1070397720.

The previous prime is 1643825453. The next prime is 1643825483. The reversal of 1643825457 is 7545283461.

1643825457 is a `hidden beast` number, since 164 + 38 + 2 + 5 + 457 = 666.

1643825457 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1643825457 - 2² = 1643825453 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643825453) 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, 2123419 + ... + 2124192.

Almost surely, 2^1643825457 is an apocalyptic number.

It is an amenable number.

1643825457 is a deficient number, since it is larger than the sum of its proper divisors (785808607).

1643825457 is a wasteful number, since it uses less digits than its factorization.

1643825457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4247660 (or 4247657 counting only the distinct ones).

The product of its digits is 806400, while the sum is 45.

The square root of 1643825457 is about 40544.1174154772. The cubic root of 1643825457 is about 1180.1899189189.

The spelling of 1643825457 in words is "one billion, six hundred forty-three million, eight hundred twenty-five thousand, four hundred fifty-seven".