645417250 has 16 divisors (see below), whose sum is σ = 1208221560. Its totient is φ = 258166800.

The previous prime is 645417247. The next prime is 645417263. The reversal of 645417250 is 52714546.

It can be written as a sum of positive squares in 4 ways, for example, as 249924481 + 395492769 = 15809^2 + 19887^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1290585 + ... + 1291084.

Almost surely, 2^645417250 is an apocalyptic number.

645417250 is a deficient number, since it is larger than the sum of its proper divisors (562804310).

645417250 is a wasteful number, since it uses less digits than its factorization.

645417250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2581686 (or 2581676 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 34.

The square root of 645417250 is about 25405.0634716782. The cubic root of 645417250 is about 864.1985292314.

The spelling of 645417250 in words is "six hundred forty-five million, four hundred seventeen thousand, two hundred fifty".