216764644 has 6 divisors (see below), whose sum is σ = 379338134. Its totient is φ = 108382320.

The previous prime is 216764629. The next prime is 216764651. The reversal of 216764644 is 446467612.

216764644 is digitally balanced in base 2, base 3 and base 9, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 206267044 + 10497600 = 14362^2 + 3240^2 .

216764644 is strictly pandigital in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 216764597 and 216764606.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27095577 + ... + 27095584.

Almost surely, 2^216764644 is an apocalyptic number.

It is an amenable number.

216764644 is a deficient number, since it is larger than the sum of its proper divisors (162573490).

216764644 is a wasteful number, since it uses less digits than its factorization.

216764644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54191165 (or 54191163 counting only the distinct ones).

The product of its digits is 193536, while the sum is 40.

The square root of 216764644 is about 14722.9291922498. The cubic root of 216764644 is about 600.7071698942.

The spelling of 216764644 in words is "two hundred sixteen million, seven hundred sixty-four thousand, six hundred forty-four".