18540797 has 4 divisors (see below), whose sum is σ = 20226336. Its totient is φ = 16855260.

The previous prime is 18540779. The next prime is 18540799. The reversal of 18540797 is 79704581.

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: 79704581 = 11 ⋅7245871.

It is a cyclic number.

It is not a de Polignac number, because 18540797 - 2¹² = 18536701 is a prime.

It is a super-2 number, since 2×18540797² = 687522306790418, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18540799) 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, 842753 + ... + 842774.

It is an arithmetic number, because the mean of its divisors is an integer number (5056584).

Almost surely, 2^18540797 is an apocalyptic number.

It is an amenable number.

18540797 is a deficient number, since it is larger than the sum of its proper divisors (1685539).

18540797 is a wasteful number, since it uses less digits than its factorization.

18540797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1685538.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 18540797 is about 4305.9025766963. The cubic root of 18540797 is about 264.6728941326.

The spelling of 18540797 in words is "eighteen million, five hundred forty thousand, seven hundred ninety-seven".