216091764 has 54 divisors (see below), whose sum is σ = 635417874. Its totient is φ = 61740000.

The previous prime is 216091741. The next prime is 216091783. The reversal of 216091764 is 467190612.

It can be written as a sum of positive squares in only one way, i.e., 216090000 + 1764 = 14700^2 + 42^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 59487 + ... + 63014.

Almost surely, 2^216091764 is an apocalyptic number.

It is an amenable number.

216091764 is an abundant number, since it is smaller than the sum of its proper divisors (419326110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216091764 is a wasteful number, since it uses less digits than its factorization.

216091764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122525 (or 122513 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 216091764 is about 14700.0599998776. The cubic root of 216091764 is about 600.0849546373.

It can be divided in two parts, 21609 and 1764, that multiplied together give a square (38118276 = 6174²).

The spelling of 216091764 in words is "two hundred sixteen million, ninety-one thousand, seven hundred sixty-four".