22116991 has 4 divisors (see below), whose sum is σ = 23818312. Its totient is φ = 20415672.

The previous prime is 22116989. The next prime is 22117003. The reversal of 22116991 is 19961122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 22116991 - 2¹ = 22116989 is a prime.

It is a super-2 number, since 2×22116991² = 978322581788162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22116191) 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, 850641 + ... + 850666.

It is an arithmetic number, because the mean of its divisors is an integer number (5954578).

Almost surely, 2^22116991 is an apocalyptic number.

22116991 is a deficient number, since it is larger than the sum of its proper divisors (1701321).

22116991 is a wasteful number, since it uses less digits than its factorization.

22116991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1701320.

The product of its digits is 1944, while the sum is 31.

The square root of 22116991 is about 4702.8705064035. The cubic root of 22116991 is about 280.6997421791.

The spelling of 22116991 in words is "twenty-two million, one hundred sixteen thousand, nine hundred ninety-one".