1640645025 has 24 divisors (see below), whose sum is σ = 2713870944. Its totient is φ = 874579200.

The previous prime is 1640644991. The next prime is 1640645029. The reversal of 1640645025 is 5205460461.

It is not a de Polignac number, because 1640645025 - 2⁸ = 1640644769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1640645029) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198985 + ... + 207065.

It is an arithmetic number, because the mean of its divisors is an integer number (113077956).

Almost surely, 2^1640645025 is an apocalyptic number.

1640645025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640645025 is a deficient number, since it is larger than the sum of its proper divisors (1073225919).

1640645025 is a wasteful number, since it uses less digits than its factorization.

1640645025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10801 (or 10796 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 1640645025 is about 40504.8765582615. The cubic root of 1640645025 is about 1179.4282936283.

The spelling of 1640645025 in words is "one billion, six hundred forty million, six hundred forty-five thousand, twenty-five".