216972637 has 6 divisors (see below), whose sum is σ = 252396798. Its totient is φ = 185976504.

The previous prime is 216972601. The next prime is 216972641. The reversal of 216972637 is 736279612.

It can be written as a sum of positive squares in only one way, i.e., 151265401 + 65707236 = 12299^2 + 8106^2 .

It is not a de Polignac number, because 216972637 - 2¹⁵ = 216939869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216972593 and 216972602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216972667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2213958 + ... + 2214055.

It is an arithmetic number, because the mean of its divisors is an integer number (42066133).

Almost surely, 2^216972637 is an apocalyptic number.

It is an amenable number.

216972637 is a deficient number, since it is larger than the sum of its proper divisors (35424161).

216972637 is an equidigital number, since it uses as much as digits as its factorization.

216972637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4428027 (or 4428020 counting only the distinct ones).

The product of its digits is 190512, while the sum is 43.

The square root of 216972637 is about 14729.9910726382. The cubic root of 216972637 is about 600.8992414163.

The spelling of 216972637 in words is "two hundred sixteen million, nine hundred seventy-two thousand, six hundred thirty-seven".