646240408 has 32 divisors (see below), whose sum is σ = 1367442000. Its totient is φ = 283615360.

The previous prime is 646240381. The next prime is 646240433. The reversal of 646240408 is 804042646.

It is a happy number.

It is a congruent 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, 124063 + ... + 129166.

Almost surely, 2^646240408 is an apocalyptic number.

It is an amenable number.

646240408 is an abundant number, since it is smaller than the sum of its proper divisors (721201592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646240408 is a wasteful number, since it uses less digits than its factorization.

646240408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253275 (or 253271 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 34.

The square root of 646240408 is about 25421.2589774779. The cubic root of 646240408 is about 864.5657695563.

The spelling of 646240408 in words is "six hundred forty-six million, two hundred forty thousand, four hundred eight".