18601021 has 2 divisors, whose sum is σ = 18601022. Its totient is φ = 18601020.

The previous prime is 18601013. The next prime is 18601027. The reversal of 18601021 is 12010681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10272025 + 8328996 = 3205^2 + 2886^2 .

It is a cyclic number.

It is not a de Polignac number, because 18601021 - 2³ = 18601013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18601021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18601027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9300510 + 9300511.

It is an arithmetic number, because the mean of its divisors is an integer number (9300511).

Almost surely, 2^18601021 is an apocalyptic number.

It is an amenable number.

18601021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18601021 is an equidigital number, since it uses as much as digits as its factorization.

18601021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

The square root of 18601021 is about 4312.8900982984. The cubic root of 18601021 is about 264.9591535477.

The spelling of 18601021 in words is "eighteen million, six hundred one thousand, twenty-one".