18932287921 has 2 divisors, whose sum is σ = 18932287922. Its totient is φ = 18932287920.

The previous prime is 18932287903. The next prime is 18932287931. The reversal of 18932287921 is 12978223981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17993539600 + 938748321 = 134140^2 + 30639^2 .

It is a cyclic number.

It is not a de Polignac number, because 18932287921 - 2⁷ = 18932287793 is a prime.

It is not a weakly prime, because it can be changed into another prime (18932287901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9466143960 + 9466143961.

It is an arithmetic number, because the mean of its divisors is an integer number (9466143961).

Almost surely, 2^18932287921 is an apocalyptic number.

It is an amenable number.

18932287921 is a deficient number, since it is larger than the sum of its proper divisors (1).

18932287921 is an equidigital number, since it uses as much as digits as its factorization.

18932287921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 52.

The spelling of 18932287921 in words is "eighteen billion, nine hundred thirty-two million, two hundred eighty-seven thousand, nine hundred twenty-one".