646989885 has 24 divisors (see below), whose sum is σ = 1170209664. Its totient is φ = 330058080.

The previous prime is 646989877. The next prime is 646989953. The reversal of 646989885 is 588989646.

646989885 is a `hidden beast` number, since 6 + 469 + 8 + 98 + 85 = 666.

It is not a de Polignac number, because 646989885 - 2³ = 646989877 is a prime.

It is a super-2 number, since 2×646989885² = 837191822584626450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 311521 + ... + 313590.

It is an arithmetic number, because the mean of its divisors is an integer number (48758736).

Almost surely, 2^646989885 is an apocalyptic number.

It is an amenable number.

646989885 is a deficient number, since it is larger than the sum of its proper divisors (523219779).

646989885 is a wasteful number, since it uses less digits than its factorization.

646989885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625145 (or 625142 counting only the distinct ones).

The product of its digits is 29859840, while the sum is 63.

The square root of 646989885 is about 25435.9958523349. The cubic root of 646989885 is about 864.8998670106.

The spelling of 646989885 in words is "six hundred forty-six million, nine hundred eighty-nine thousand, eight hundred eighty-five".