21456345431 has 4 divisors (see below), whose sum is σ = 21457098432. Its totient is φ = 21455592432.

The previous prime is 21456345413. The next prime is 21456345467. The reversal of 21456345431 is 13454365412.

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 21456345431 - 2⁶ = 21456345367 is a prime.

It is a super-2 number, since 2×21456345431² (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 (21456345331) 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, 332006 + ... + 391331.

It is an arithmetic number, because the mean of its divisors is an integer number (5364274608).

Almost surely, 2^21456345431 is an apocalyptic number.

21456345431 is a deficient number, since it is larger than the sum of its proper divisors (753001).

21456345431 is an equidigital number, since it uses as much as digits as its factorization.

21456345431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753000.

The product of its digits is 172800, while the sum is 38.

The spelling of 21456345431 in words is "twenty-one billion, four hundred fifty-six million, three hundred forty-five thousand, four hundred thirty-one".