18995021 has 2 divisors, whose sum is σ = 18995022. Its totient is φ = 18995020.

The previous prime is 18994999. The next prime is 18995027. The reversal of 18995021 is 12059981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18826921 + 168100 = 4339^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 18995021 - 2¹⁴ = 18978637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18995027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9497510 + 9497511.

It is an arithmetic number, because the mean of its divisors is an integer number (9497511).

Almost surely, 2^18995021 is an apocalyptic number.

It is an amenable number.

18995021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18995021 is an equidigital number, since it uses as much as digits as its factorization.

18995021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 18995021 is about 4358.3277756497. The cubic root of 18995021 is about 266.8168541134.

The spelling of 18995021 in words is "eighteen million, nine hundred ninety-five thousand, twenty-one".