646457290 has 8 divisors (see below), whose sum is σ = 1163623140. Its totient is φ = 258582912.

The previous prime is 646457261. The next prime is 646457323. The reversal of 646457290 is 92754646.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 641254329 + 5202961 = 25323^2 + 2281^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32322855 + ... + 32322874.

Almost surely, 2^646457290 is an apocalyptic number.

646457290 is a deficient number, since it is larger than the sum of its proper divisors (517165850).

646457290 is a wasteful number, since it uses less digits than its factorization.

646457290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64645736.

The product of its (nonzero) digits is 362880, while the sum is 43.

The square root of 646457290 is about 25425.5243800398. The cubic root of 646457290 is about 864.6624764879.

The spelling of 646457290 in words is "six hundred forty-six million, four hundred fifty-seven thousand, two hundred ninety".