640455441 has 8 divisors (see below), whose sum is σ = 854436384. Its totient is φ = 426722400.

The previous prime is 640455437. The next prime is 640455451. The reversal of 640455441 is 144554046.

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

It is not a de Polignac number, because 640455441 - 2² = 640455437 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640455451) 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, 55860 + ... + 66341.

It is an arithmetic number, because the mean of its divisors is an integer number (106804548).

Almost surely, 2^640455441 is an apocalyptic number.

It is an amenable number.

640455441 is a deficient number, since it is larger than the sum of its proper divisors (213980943).

640455441 is a wasteful number, since it uses less digits than its factorization.

640455441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123951.

The product of its (nonzero) digits is 38400, while the sum is 33.

The square root of 640455441 is about 25307.2211236240. The cubic root of 640455441 is about 861.9782479353.

The spelling of 640455441 in words is "six hundred forty million, four hundred fifty-five thousand, four hundred forty-one".