216979449 has 16 divisors (see below), whose sum is σ = 322447680. Its totient is φ = 128977920.

The previous prime is 216979409. The next prime is 216979453. The reversal of 216979449 is 944979612.

It is a happy number.

It is not a de Polignac number, because 216979449 - 2⁸ = 216979193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (216979409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110992 + ... + 112929.

It is an arithmetic number, because the mean of its divisors is an integer number (20152980).

Almost surely, 2^216979449 is an apocalyptic number.

It is an amenable number.

216979449 is a deficient number, since it is larger than the sum of its proper divisors (105468231).

216979449 is a wasteful number, since it uses less digits than its factorization.

216979449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223960.

The product of its digits is 979776, while the sum is 51.

The square root of 216979449 is about 14730.2222997482. Note that the first 4 decimals coincide. The cubic root of 216979449 is about 600.9055298941.

It can be divided in two parts, 2169 and 79449, that added together give a palindrome (81618).

The spelling of 216979449 in words is "two hundred sixteen million, nine hundred seventy-nine thousand, four hundred forty-nine".