117216921 has 32 divisors (see below), whose sum is σ = 172302336. Its totient is φ = 70560000.

The previous prime is 117216917. The next prime is 117216949. The reversal of 117216921 is 129612711.

It is not a de Polignac number, because 117216921 - 2² = 117216917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (117216721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 238486 + ... + 238976.

It is an arithmetic number, because the mean of its divisors is an integer number (5384448).

Almost surely, 2^117216921 is an apocalyptic number.

It is an amenable number.

117216921 is a deficient number, since it is larger than the sum of its proper divisors (55085415).

117216921 is a wasteful number, since it uses less digits than its factorization.

117216921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693.

The product of its digits is 1512, while the sum is 30.

The square root of 117216921 is about 10826.6763598068. The cubic root of 117216921 is about 489.3994043668.

The spelling of 117216921 in words is "one hundred seventeen million, two hundred sixteen thousand, nine hundred twenty-one".