21225351399 has 16 divisors (see below), whose sum is σ = 32357295360. Its totient is φ = 12123558720.

The previous prime is 21225351359. The next prime is 21225351443. The reversal of 21225351399 is 99315352212.

It is not a de Polignac number, because 21225351399 - 2²³ = 21216962791 is a prime.

It is a super-2 number, since 2×21225351399² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21225351399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21225351359) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166942 + ... + 265179.

It is an arithmetic number, because the mean of its divisors is an integer number (2022330960).

Almost surely, 2^21225351399 is an apocalyptic number.

21225351399 is a deficient number, since it is larger than the sum of its proper divisors (11131943961).

21225351399 is a wasteful number, since it uses less digits than its factorization.

21225351399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434470.

The product of its digits is 145800, while the sum is 42.

The spelling of 21225351399 in words is "twenty-one billion, two hundred twenty-five million, three hundred fifty-one thousand, three hundred ninety-nine".