18456397 has 4 divisors (see below), whose sum is σ = 18552220. Its totient is φ = 18360576.

The previous prime is 18456337. The next prime is 18456409. The reversal of 18456397 is 79365481.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1572516 + 16883881 = 1254^2 + 4109^2 .

It is a cyclic number.

It is not a de Polignac number, because 18456397 - 2²³ = 10067789 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 (18456337) 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, 47622 + ... + 48007.

It is an arithmetic number, because the mean of its divisors is an integer number (4638055).

Almost surely, 2^18456397 is an apocalyptic number.

It is an amenable number.

18456397 is a deficient number, since it is larger than the sum of its proper divisors (95823).

18456397 is an equidigital number, since it uses as much as digits as its factorization.

18456397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95822.

The product of its digits is 181440, while the sum is 43.

The square root of 18456397 is about 4296.0908975486. The cubic root of 18456397 is about 264.2706752860.

The spelling of 18456397 in words is "eighteen million, four hundred fifty-six thousand, three hundred ninety-seven".