18232021 has 2 divisors, whose sum is σ = 18232022. Its totient is φ = 18232020.

The previous prime is 18231991. The next prime is 18232063. The reversal of 18232021 is 12023281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12327121 + 5904900 = 3511^2 + 2430^2 .

It is an emirp because it is prime and its reverse (12023281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18232021 - 2⁵ = 18231989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18232021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18233021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9116010 + 9116011.

It is an arithmetic number, because the mean of its divisors is an integer number (9116011).

Almost surely, 2^18232021 is an apocalyptic number.

It is an amenable number.

18232021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18232021 is an equidigital number, since it uses as much as digits as its factorization.

18232021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 18232021 is about 4269.8970713590. The cubic root of 18232021 is about 263.1953855632.

It can be divided in two parts, 1823 and 2021, that added together give a square (3844 = 62²).

The spelling of 18232021 in words is "eighteen million, two hundred thirty-two thousand, twenty-one".