21654013399 has 4 divisors (see below), whose sum is σ = 21856387464. Its totient is φ = 21451639336.

The previous prime is 21654013397. The next prime is 21654013411. The reversal of 21654013399 is 99331045612.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21654013399 - 2¹ = 21654013397 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 (21654013397) 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 in 3 ways as a sum of consecutive naturals, for example, 101186872 + ... + 101187085.

It is an arithmetic number, because the mean of its divisors is an integer number (5464096866).

Almost surely, 2^21654013399 is an apocalyptic number.

21654013399 is a deficient number, since it is larger than the sum of its proper divisors (202374065).

21654013399 is a wasteful number, since it uses less digits than its factorization.

21654013399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202374064.

The product of its (nonzero) digits is 174960, while the sum is 43.

The spelling of 21654013399 in words is "twenty-one billion, six hundred fifty-four million, thirteen thousand, three hundred ninety-nine".