216117621 has 12 divisors (see below), whose sum is σ = 312324480. Its totient is φ = 144007080.

The previous prime is 216117611. The next prime is 216117631. The reversal of 216117621 is 126711612.

It is a happy number.

216117621 is a `hidden beast` number, since 21 + 6 + 1 + 17 + 621 = 666.

It is an interprime number because it is at equal distance from previous prime (216117611) and next prime (216117631).

It is not a de Polignac number, because 216117621 - 2⁵ = 216117589 is a prime.

It is a super-2 number, since 2×216117621² = 93413652213399282, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216117611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18556 + ... + 27866.

It is an arithmetic number, because the mean of its divisors is an integer number (26027040).

Almost surely, 2^216117621 is an apocalyptic number.

It is an amenable number.

216117621 is a deficient number, since it is larger than the sum of its proper divisors (96206859).

216117621 is a wasteful number, since it uses less digits than its factorization.

216117621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11896 (or 11893 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 216117621 is about 14700.9394597760. The cubic root of 216117621 is about 600.1088885709.

The spelling of 216117621 in words is "two hundred sixteen million, one hundred seventeen thousand, six hundred twenty-one".