216651644 has 12 divisors (see below), whose sum is σ = 413607768. Its totient is φ = 98478000.

The previous prime is 216651641. The next prime is 216651649. The reversal of 216651644 is 446156612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216651641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2461907 + ... + 2461994.

It is an arithmetic number, because the mean of its divisors is an integer number (34467314).

Almost surely, 2^216651644 is an apocalyptic number.

It is an amenable number.

216651644 is a deficient number, since it is larger than the sum of its proper divisors (196956124).

216651644 is a wasteful number, since it uses less digits than its factorization.

216651644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4923916 (or 4923914 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

The square root of 216651644 is about 14719.0911404203. The cubic root of 216651644 is about 600.6027683219.

The spelling of 216651644 in words is "two hundred sixteen million, six hundred fifty-one thousand, six hundred forty-four".