216886649 has 4 divisors (see below), whose sum is σ = 247870464. Its totient is φ = 185902836.

The previous prime is 216886643. The next prime is 216886661. The reversal of 216886649 is 946688612.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 216886649 - 2¹² = 216882553 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216886597 and 216886606.

It is not an unprimeable number, because it can be changed into a prime (216886643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15491897 + ... + 15491910.

It is an arithmetic number, because the mean of its divisors is an integer number (61967616).

Almost surely, 2^216886649 is an apocalyptic number.

It is an amenable number.

216886649 is a deficient number, since it is larger than the sum of its proper divisors (30983815).

216886649 is an equidigital number, since it uses as much as digits as its factorization.

216886649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30983814.

The product of its digits is 995328, while the sum is 50.

The square root of 216886649 is about 14727.0719764657. The cubic root of 216886649 is about 600.8198505279.

The spelling of 216886649 in words is "two hundred sixteen million, eight hundred eighty-six thousand, six hundred forty-nine".