18772291 has 2 divisors, whose sum is σ = 18772292. Its totient is φ = 18772290.

The previous prime is 18772289. The next prime is 18772297. The reversal of 18772291 is 19227781.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18772291 - 2¹ = 18772289 is a prime.

Together with 18772289, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18772291.

It is not a weakly prime, because it can be changed into another prime (18772297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9386145 + 9386146.

It is an arithmetic number, because the mean of its divisors is an integer number (9386146).

Almost surely, 2^18772291 is an apocalyptic number.

18772291 is a deficient number, since it is larger than the sum of its proper divisors (1).

18772291 is an equidigital number, since it uses as much as digits as its factorization.

18772291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 37.

The square root of 18772291 is about 4332.7001973365. The cubic root of 18772291 is about 265.7698793680.

The spelling of 18772291 in words is "eighteen million, seven hundred seventy-two thousand, two hundred ninety-one".