18491297 has 4 divisors (see below), whose sum is σ = 20172336. Its totient is φ = 16810260.

The previous prime is 18491273. The next prime is 18491323. The reversal of 18491297 is 79219481.

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.

It is a cyclic number.

It is not a de Polignac number, because 18491297 - 2⁶ = 18491233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18491227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 840503 + ... + 840524.

It is an arithmetic number, because the mean of its divisors is an integer number (5043084).

Almost surely, 2^18491297 is an apocalyptic number.

It is an amenable number.

18491297 is a deficient number, since it is larger than the sum of its proper divisors (1681039).

18491297 is a wasteful number, since it uses less digits than its factorization.

18491297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1681038.

The product of its digits is 36288, while the sum is 41.

The square root of 18491297 is about 4300.1508113088. The cubic root of 18491297 is about 264.4371440222.

The spelling of 18491297 in words is "eighteen million, four hundred ninety-one thousand, two hundred ninety-seven".