18949397 has 4 divisors (see below), whose sum is σ = 19016640. Its totient is φ = 18882156.

The previous prime is 18949391. The next prime is 18949417. The reversal of 18949397 is 79394981.

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, and also an emirpimes, since its reverse is a distinct semiprime: 79394981 = 17 ⋅4670293.

It is a cyclic number.

It is not a de Polignac number, because 18949397 - 2²² = 14755093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18949391) 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, 33197 + ... + 33762.

It is an arithmetic number, because the mean of its divisors is an integer number (4754160).

Almost surely, 2^18949397 is an apocalyptic number.

It is an amenable number.

18949397 is a deficient number, since it is larger than the sum of its proper divisors (67243).

18949397 is an equidigital number, since it uses as much as digits as its factorization.

18949397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67242.

The product of its digits is 489888, while the sum is 50.

The square root of 18949397 is about 4353.0905113494. The cubic root of 18949397 is about 266.6030610452.

The spelling of 18949397 in words is "eighteen million, nine hundred forty-nine thousand, three hundred ninety-seven".