21219274399 has 2 divisors, whose sum is σ = 21219274400. Its totient is φ = 21219274398.

The previous prime is 21219274367. The next prime is 21219274471. The reversal of 21219274399 is 99347291212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21219274399 - 2⁵ = 21219274367 is a prime.

It is a super-2 number, since 2×21219274399² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21219271399) 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, 10609637199 + 10609637200.

It is an arithmetic number, because the mean of its divisors is an integer number (10609637200).

Almost surely, 2^21219274399 is an apocalyptic number.

21219274399 is a deficient number, since it is larger than the sum of its proper divisors (1).

21219274399 is an equidigital number, since it uses as much as digits as its factorization.

21219274399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 49.

The spelling of 21219274399 in words is "twenty-one billion, two hundred nineteen million, two hundred seventy-four thousand, three hundred ninety-nine".