1640520025 has 12 divisors (see below), whose sum is σ = 2034962512. Its totient is φ = 1311953040.

The previous prime is 1640519989. The next prime is 1640520067. The reversal of 1640520025 is 5200250461.

It is not a de Polignac number, because 1640520025 - 2⁹ = 1640519513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72754 + ... + 92596.

Almost surely, 2^1640520025 is an apocalyptic number.

It is an amenable number.

1640520025 is a deficient number, since it is larger than the sum of its proper divisors (394442487).

1640520025 is a wasteful number, since it uses less digits than its factorization.

1640520025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23160 (or 23155 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 1640520025 is about 40503.3335047870. Note that the first 3 decimals coincide. The cubic root of 1640520025 is about 1179.3983394988.

Adding to 1640520025 its reverse (5200250461), we get a palindrome (6840770486).

The spelling of 1640520025 in words is "one billion, six hundred forty million, five hundred twenty thousand, twenty-five".