645420425 has 24 divisors (see below), whose sum is σ = 863408280. Its totient is φ = 475776000.

The previous prime is 645420409. The next prime is 645420449. The reversal of 645420425 is 524024546.

It can be written as a sum of positive squares in 12 ways, for example, as 415018384 + 230402041 = 20372^2 + 15179^2 .

It is not a de Polignac number, because 645420425 - 2⁴ = 645420409 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645420391 and 645420400.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 229025 + ... + 231825.

It is an arithmetic number, because the mean of its divisors is an integer number (35975345).

Almost surely, 2^645420425 is an apocalyptic number.

645420425 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

645420425 is a deficient number, since it is larger than the sum of its proper divisors (217987855).

645420425 is a wasteful number, since it uses less digits than its factorization.

645420425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3533 (or 3528 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 32.

The square root of 645420425 is about 25405.1259591445. The cubic root of 645420425 is about 864.1999463126.

The spelling of 645420425 in words is "six hundred forty-five million, four hundred twenty thousand, four hundred twenty-five".