216649756 has 12 divisors (see below), whose sum is σ = 379268568. Its totient is φ = 108287312.

The previous prime is 216649739. The next prime is 216649757. The reversal of 216649756 is 657946612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216649757) by changing a digit.

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, 6615 + ... + 21841.

It is an arithmetic number, because the mean of its divisors is an integer number (31605714).

Almost surely, 2^216649756 is an apocalyptic number.

It is an amenable number.

216649756 is a deficient number, since it is larger than the sum of its proper divisors (162618812).

216649756 is a wasteful number, since it uses less digits than its factorization.

216649756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18788 (or 18786 counting only the distinct ones).

The product of its digits is 544320, while the sum is 46.

The square root of 216649756 is about 14719.0270058860. The cubic root of 216649756 is about 600.6010236758.

The spelling of 216649756 in words is "two hundred sixteen million, six hundred forty-nine thousand, seven hundred fifty-six".