18601381 has 4 divisors (see below), whose sum is σ = 18668812. Its totient is φ = 18533952.

The previous prime is 18601321. The next prime is 18601409. The reversal of 18601381 is 18310681.

It is a happy number.

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 3740356 + 14861025 = 1934^2 + 3855^2 .

It is a cyclic number.

It is not a de Polignac number, because 18601381 - 2¹¹ = 18599333 is a prime.

It is a super-2 number, since 2×18601381² = 692022750214322, 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 (18601301) 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, 33300 + ... + 33853.

It is an arithmetic number, because the mean of its divisors is an integer number (4667203).

Almost surely, 2^18601381 is an apocalyptic number.

It is an amenable number.

18601381 is a deficient number, since it is larger than the sum of its proper divisors (67431).

18601381 is an equidigital number, since it uses as much as digits as its factorization.

18601381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67430.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 18601381 is about 4312.9318334516. The cubic root of 18601381 is about 264.9608628567.

The spelling of 18601381 in words is "eighteen million, six hundred one thousand, three hundred eighty-one".