21634533399 has 4 divisors (see below), whose sum is σ = 28846044536. Its totient is φ = 14423022264.

The previous prime is 21634533377. The next prime is 21634533409. The reversal of 21634533399 is 99333543612.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21634533399 - 2⁸ = 21634533143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634523399) 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 in 3 ways as a sum of consecutive naturals, for example, 3605755564 + ... + 3605755569.

It is an arithmetic number, because the mean of its divisors is an integer number (7211511134).

Almost surely, 2^21634533399 is an apocalyptic number.

21634533399 is a deficient number, since it is larger than the sum of its proper divisors (7211511137).

21634533399 is an equidigital number, since it uses as much as digits as its factorization.

21634533399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7211511136.

The product of its digits is 1574640, while the sum is 48.

The spelling of 21634533399 in words is "twenty-one billion, six hundred thirty-four million, five hundred thirty-three thousand, three hundred ninety-nine".