17996991 has 8 divisors (see below), whose sum is σ = 24581424. Its totient is φ = 11705280.

The previous prime is 17996987. The next prime is 17997037. The reversal of 17996991 is 19969971.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 17996991 - 2² = 17996987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17996941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73036 + ... + 73281.

It is an arithmetic number, because the mean of its divisors is an integer number (3072678).

Almost surely, 2^17996991 is an apocalyptic number.

17996991 is a deficient number, since it is larger than the sum of its proper divisors (6584433).

17996991 is a wasteful number, since it uses less digits than its factorization.

17996991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146361.

The product of its digits is 275562, while the sum is 51.

The square root of 17996991 is about 4242.2860582474. The cubic root of 17996991 is about 262.0595352536.

The spelling of 17996991 in words is "seventeen million, nine hundred ninety-six thousand, nine hundred ninety-one".