21554336431 has 6 divisors (see below), whose sum is σ = 22896821360. Its totient is φ = 20286434016.

The previous prime is 21554336407. The next prime is 21554336513. The reversal of 21554336431 is 13463345512.

It is not a de Polignac number, because 21554336431 - 2⁵ = 21554336399 is a prime.

It is a super-2 number, since 2×21554336431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554336831) 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 5 ways as a sum of consecutive naturals, for example, 37290951 + ... + 37291528.

Almost surely, 2^21554336431 is an apocalyptic number.

21554336431 is a deficient number, since it is larger than the sum of its proper divisors (1342484929).

21554336431 is an equidigital number, since it uses as much as digits as its factorization.

21554336431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74582513 (or 74582496 counting only the distinct ones).

The product of its digits is 129600, while the sum is 37.

The spelling of 21554336431 in words is "twenty-one billion, five hundred fifty-four million, three hundred thirty-six thousand, four hundred thirty-one".