640451274 has 8 divisors (see below), whose sum is σ = 1280902560. Its totient is φ = 213483756.

The previous prime is 640451269. The next prime is 640451291. The reversal of 640451274 is 472154046.

It is a sphenic number, since it is the product of 3 distinct primes.

640451274 is an admirable number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53370934 + ... + 53370945.

It is an arithmetic number, because the mean of its divisors is an integer number (160112820).

Almost surely, 2^640451274 is an apocalyptic number.

640451274 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

640451274 is a wasteful number, since it uses less digits than its factorization.

640451274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106741884.

The product of its (nonzero) digits is 26880, while the sum is 33.

The square root of 640451274 is about 25307.1387952095. The cubic root of 640451274 is about 861.9763784994.

The spelling of 640451274 in words is "six hundred forty million, four hundred fifty-one thousand, two hundred seventy-four".