646090540 has 24 divisors (see below), whose sum is σ = 1357650000. Its totient is φ = 258272448.

The previous prime is 646090517. The next prime is 646090553. The reversal of 646090540 is 45090646.

It is a junction number, because it is equal to n+sod(n) for n = 646090496 and 646090505.

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 7 ways as a sum of consecutive naturals, for example, 25086 + ... + 43834.

It is an arithmetic number, because the mean of its divisors is an integer number (56568750).

Almost surely, 2^646090540 is an apocalyptic number.

It is an amenable number.

646090540 is an abundant number, since it is smaller than the sum of its proper divisors (711559460).

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

646090540 is a wasteful number, since it uses less digits than its factorization.

646090540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20481 (or 20479 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 646090540 is about 25418.3111162012. The cubic root of 646090540 is about 864.4989312927.

The spelling of 646090540 in words is "six hundred forty-six million, ninety thousand, five hundred forty".