21254355431 has 4 divisors (see below), whose sum is σ = 21254964000. Its totient is φ = 21253746864.

The previous prime is 21254355401. The next prime is 21254355481. The reversal of 21254355431 is 13455345212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21254355431 is a prime.

It is a super-2 number, since 2×21254355431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21254355391 and 21254355400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254355401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248486 + ... + 322883.

It is an arithmetic number, because the mean of its divisors is an integer number (5313741000).

Almost surely, 2^21254355431 is an apocalyptic number.

21254355431 is a deficient number, since it is larger than the sum of its proper divisors (608569).

21254355431 is an equidigital number, since it uses as much as digits as its factorization.

21254355431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608568.

The product of its digits is 72000, while the sum is 35.

The spelling of 21254355431 in words is "twenty-one billion, two hundred fifty-four million, three hundred fifty-five thousand, four hundred thirty-one".