1640000025 has 72 divisors (see below), whose sum is σ = 3121299480. Its totient is φ = 821560320.

The previous prime is 1640000017. The next prime is 1640000039. The reversal of 1640000025 is 5200000461.

It is a happy number.

1640000025 is a `hidden beast` number, since 1 + 640 + 0 + 0 + 0 + 0 + 25 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 410305536 + 1229694489 = 20256^2 + 35067^2 .

It is not a de Polignac number, because 1640000025 - 2³ = 1640000017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1639999962 and 1640000007.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 238029 + ... + 244821.

Almost surely, 2^1640000025 is an apocalyptic number.

1640000025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640000025 is a deficient number, since it is larger than the sum of its proper divisors (1481299455).

1640000025 is a wasteful number, since it uses less digits than its factorization.

1640000025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6875 (or 6867 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 1640000025 is about 40496.9137712987. The cubic root of 1640000025 is about 1179.2737139863.

Adding to 1640000025 its reverse (5200000461), we get a palindrome (6840000486).

The spelling of 1640000025 in words is "one billion, six hundred forty million, twenty-five", and thus it is an aban number.