21198930391 has 2 divisors, whose sum is σ = 21198930392. Its totient is φ = 21198930390.

The previous prime is 21198930349. The next prime is 21198930409. The reversal of 21198930391 is 19303989112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21198930391 - 2⁹ = 21198929879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21198930091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10599465195 + 10599465196.

It is an arithmetic number, because the mean of its divisors is an integer number (10599465196).

Almost surely, 2^21198930391 is an apocalyptic number.

21198930391 is a deficient number, since it is larger than the sum of its proper divisors (1).

21198930391 is an equidigital number, since it uses as much as digits as its factorization.

21198930391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 46.

The spelling of 21198930391 in words is "twenty-one billion, one hundred ninety-eight million, nine hundred thirty thousand, three hundred ninety-one".