21401324499 has 4 divisors (see below), whose sum is σ = 28535099336. Its totient is φ = 14267549664.

The previous prime is 21401324479. The next prime is 21401324507. The reversal of 21401324499 is 99442310412.

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

It is a de Polignac number, because none of the positive numbers 2^k-21401324499 is a prime.

It is a super-2 number, since 2×21401324499² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21401324419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3566887414 + ... + 3566887419.

It is an arithmetic number, because the mean of its divisors is an integer number (7133774834).

Almost surely, 2^21401324499 is an apocalyptic number.

21401324499 is a deficient number, since it is larger than the sum of its proper divisors (7133774837).

21401324499 is an equidigital number, since it uses as much as digits as its factorization.

21401324499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7133774836.

The product of its (nonzero) digits is 62208, while the sum is 39.

The spelling of 21401324499 in words is "twenty-one billion, four hundred one million, three hundred twenty-four thousand, four hundred ninety-nine".