640925298 has 80 divisors (see below), whose sum is σ = 1553709696. Its totient is φ = 196305120.

The previous prime is 640925267. The next prime is 640925333. The reversal of 640925298 is 892529046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 570165 + ... + 571287.

Almost surely, 2^640925298 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640925298, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (776854848).

640925298 is an abundant number, since it is smaller than the sum of its proper divisors (912784398).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640925298 is a wasteful number, since it uses less digits than its factorization.

640925298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1421 (or 1412 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 640925298 is about 25316.5024835580. The cubic root of 640925298 is about 862.1889872969.

The spelling of 640925298 in words is "six hundred forty million, nine hundred twenty-five thousand, two hundred ninety-eight".