640174251 has 8 divisors (see below), whose sum is σ = 859003024. Its totient is φ = 424064160.

The previous prime is 640174247. The next prime is 640174291. The reversal of 640174251 is 152471046.

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

It is not a de Polignac number, because 640174251 - 2² = 640174247 is a prime.

It is a super-2 number, since 2×640174251² = 819646143286822002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640174231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 679120 + ... + 680061.

It is an arithmetic number, because the mean of its divisors is an integer number (107375378).

Almost surely, 2^640174251 is an apocalyptic number.

640174251 is a deficient number, since it is larger than the sum of its proper divisors (218828773).

640174251 is a wasteful number, since it uses less digits than its factorization.

640174251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1359341.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 640174251 is about 25301.6649847396. The cubic root of 640174251 is about 861.8520798322.

The spelling of 640174251 in words is "six hundred forty million, one hundred seventy-four thousand, two hundred fifty-one".