646429090 has 16 divisors (see below), whose sum is σ = 1165099320. Its totient is φ = 258232320.

The previous prime is 646429087. The next prime is 646429093. The reversal of 646429090 is 90924646.

646429090 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (646429087) and next prime (646429093).

It can be written as a sum of positive squares in 4 ways, for example, as 287743369 + 358685721 = 16963^2 + 18939^2 .

It is not an unprimeable number, because it can be changed into a prime (646429093) 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, 34341 + ... + 49720.

Almost surely, 2^646429090 is an apocalyptic number.

646429090 is a deficient number, since it is larger than the sum of its proper divisors (518670230).

646429090 is a wasteful number, since it uses less digits than its factorization.

646429090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84837.

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 646429090 is about 25424.9698131581. The cubic root of 646429090 is about 864.6499034292.

The spelling of 646429090 in words is "six hundred forty-six million, four hundred twenty-nine thousand, ninety".