18780481 has 4 divisors (see below), whose sum is σ = 18811732. Its totient is φ = 18749232.

The previous prime is 18780479. The next prime is 18780523. The reversal of 18780481 is 18408781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18408781 = 2447 ⋅7523.

It can be written as a sum of positive squares in 2 ways, for example, as 7890481 + 10890000 = 2809^2 + 3300^2 .

It is a cyclic number.

It is not a de Polignac number, because 18780481 - 2¹ = 18780479 is a prime.

It is a super-2 number, since 2×18780481² = 705412933182722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18780481.

It is not an unprimeable number, because it can be changed into a prime (18780431) 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, 14706 + ... + 15931.

It is an arithmetic number, because the mean of its divisors is an integer number (4702933).

Almost surely, 2^18780481 is an apocalyptic number.

It is an amenable number.

18780481 is a deficient number, since it is larger than the sum of its proper divisors (31251).

18780481 is an equidigital number, since it uses as much as digits as its factorization.

18780481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31250.

The product of its (nonzero) digits is 14336, while the sum is 37.

The square root of 18780481 is about 4333.6452323650. The cubic root of 18780481 is about 265.8085238937.

The spelling of 18780481 in words is "eighteen million, seven hundred eighty thousand, four hundred eighty-one".