640023355 has 8 divisors (see below), whose sum is σ = 769276512. Its totient is φ = 511186368.

The previous prime is 640023347. The next prime is 640023401. The reversal of 640023355 is 553320046.

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 640023355 - 2³ = 640023347 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100647 + ... + 106816.

It is an arithmetic number, because the mean of its divisors is an integer number (96159564).

Almost surely, 2^640023355 is an apocalyptic number.

640023355 is a deficient number, since it is larger than the sum of its proper divisors (129253157).

640023355 is a wasteful number, since it uses less digits than its factorization.

640023355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208085.

The product of its (nonzero) digits is 10800, while the sum is 28.

The square root of 640023355 is about 25298.6828708532. The cubic root of 640023355 is about 861.7843585565.

The spelling of 640023355 in words is "six hundred forty million, twenty-three thousand, three hundred fifty-five".