117667721 has 4 divisors (see below), whose sum is σ = 118083792. Its totient is φ = 117251652.

The previous prime is 117667717. The next prime is 117667763. The reversal of 117667721 is 127766711.

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, and also an emirpimes, since its reverse is a distinct semiprime: 127766711 = 1409 ⋅90679.

It is a cyclic number.

It is not a de Polignac number, because 117667721 - 2² = 117667717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (117667321) 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, 207611 + ... + 208176.

It is an arithmetic number, because the mean of its divisors is an integer number (29520948).

Almost surely, 2^117667721 is an apocalyptic number.

It is an amenable number.

117667721 is a deficient number, since it is larger than the sum of its proper divisors (416071).

117667721 is an equidigital number, since it uses as much as digits as its factorization.

117667721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416070.

The product of its digits is 24696, while the sum is 38.

The square root of 117667721 is about 10847.4753283886. The cubic root of 117667721 is about 490.0259891810.

The spelling of 117667721 in words is "one hundred seventeen million, six hundred sixty-seven thousand, seven hundred twenty-one".