216606538 has 4 divisors (see below), whose sum is σ = 324909810. Its totient is φ = 108303268.

The previous prime is 216606499. The next prime is 216606541. The reversal of 216606538 is 835606612.

216606538 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 214710409 + 1896129 = 14653^2 + 1377^2 .

It is a junction number, because it is equal to n+sod(n) for n = 216606497 and 216606506.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54151633 + ... + 54151636.

Almost surely, 2^216606538 is an apocalyptic number.

216606538 is a deficient number, since it is larger than the sum of its proper divisors (108303272).

216606538 is a wasteful number, since it uses less digits than its factorization.

216606538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108303271.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 216606538 is about 14717.5588329043. The cubic root of 216606538 is about 600.5610844029.

The spelling of 216606538 in words is "two hundred sixteen million, six hundred six thousand, five hundred thirty-eight".