640274253 has 8 divisors (see below), whose sum is σ = 890816448. Its totient is φ = 408290784.

The previous prime is 640274203. The next prime is 640274263. The reversal of 640274253 is 352472046.

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

It is not a de Polignac number, because 640274253 - 2⁶ = 640274189 is a prime.

It is a super-2 number, since 2×640274253² = 819902238109416018, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640274203) 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, 4639600 + ... + 4639737.

It is an arithmetic number, because the mean of its divisors is an integer number (111352056).

Almost surely, 2^640274253 is an apocalyptic number.

It is an amenable number.

640274253 is a deficient number, since it is larger than the sum of its proper divisors (250542195).

640274253 is a wasteful number, since it uses less digits than its factorization.

640274253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9279363.

The product of its (nonzero) digits is 40320, while the sum is 33.

The square root of 640274253 is about 25303.6411016280. The cubic root of 640274253 is about 861.8969543041.

The spelling of 640274253 in words is "six hundred forty million, two hundred seventy-four thousand, two hundred fifty-three".