646732690 has 32 divisors (see below), whose sum is σ = 1191884544. Its totient is φ = 252551040.

The previous prime is 646732673. The next prime is 646732693. The reversal of 646732690 is 96237646.

It is a super-2 number, since 2×646732690² = 836526344629272200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (646732693) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 213285 + ... + 216295.

It is an arithmetic number, because the mean of its divisors is an integer number (37246392).

Almost surely, 2^646732690 is an apocalyptic number.

646732690 is a deficient number, since it is larger than the sum of its proper divisors (545151854).

646732690 is a wasteful number, since it uses less digits than its factorization.

646732690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3522.

The product of its (nonzero) digits is 326592, while the sum is 43.

The square root of 646732690 is about 25430.9396208634. The cubic root of 646732690 is about 864.7852452268.

The spelling of 646732690 in words is "six hundred forty-six million, seven hundred thirty-two thousand, six hundred ninety".