640453251 has 8 divisors (see below), whose sum is σ = 874765584. Its totient is φ = 416554880.

The previous prime is 640453249. The next prime is 640453283. The reversal of 640453251 is 152354046.

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

It is a cyclic number.

It is not a de Polignac number, because 640453251 - 2¹ = 640453249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640453351) 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, 2603346 + ... + 2603591.

It is an arithmetic number, because the mean of its divisors is an integer number (109345698).

Almost surely, 2^640453251 is an apocalyptic number.

640453251 is a deficient number, since it is larger than the sum of its proper divisors (234312333).

640453251 is a wasteful number, since it uses less digits than its factorization.

640453251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5206981.

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 640453251 is about 25307.1778553042. The cubic root of 640453251 is about 861.9772654394.

The spelling of 640453251 in words is "six hundred forty million, four hundred fifty-three thousand, two hundred fifty-one".