17981397 has 24 divisors (see below), whose sum is σ = 30176640. Its totient is φ = 10104480.

The previous prime is 17981357. The next prime is 17981399. The reversal of 17981397 is 79318971.

It is not a de Polignac number, because 17981397 - 2¹⁵ = 17948629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17981399) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1504 + ... + 6182.

It is an arithmetic number, because the mean of its divisors is an integer number (1257360).

Almost surely, 2^17981397 is an apocalyptic number.

It is an amenable number.

17981397 is a deficient number, since it is larger than the sum of its proper divisors (12195243).

17981397 is a wasteful number, since it uses less digits than its factorization.

17981397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4753 (or 4750 counting only the distinct ones).

The product of its digits is 95256, while the sum is 45.

The square root of 17981397 is about 4240.4477357939. The cubic root of 17981397 is about 261.9838237590.

The spelling of 17981397 in words is "seventeen million, nine hundred eighty-one thousand, three hundred ninety-seven".