642745625 has 10 divisors (see below), whose sum is σ = 803175714. Its totient is φ = 514196000.

The previous prime is 642745601. The next prime is 642745627. The reversal of 642745625 is 526547246.

It can be written as a sum of positive squares in 5 ways, for example, as 456805129 + 185940496 = 21373^2 + 13636^2 .

It is not a de Polignac number, because 642745625 - 2¹⁸ = 642483481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642745627) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 513572 + ... + 514821.

Almost surely, 2^642745625 is an apocalyptic number.

It is an amenable number.

642745625 is a deficient number, since it is larger than the sum of its proper divisors (160430089).

642745625 is an equidigital number, since it uses as much as digits as its factorization.

642745625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1028413 (or 1028398 counting only the distinct ones).

The product of its digits is 403200, while the sum is 41.

The square root of 642745625 is about 25352.4283846735. The cubic root of 642745625 is about 863.0044657911.

The spelling of 642745625 in words is "six hundred forty-two million, seven hundred forty-five thousand, six hundred twenty-five".