21431715254 has 4 divisors (see below), whose sum is σ = 32147572884. Its totient is φ = 10715857626.

The previous prime is 21431715251. The next prime is 21431715257. The reversal of 21431715254 is 45251713412.

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

It is an interprime number because it is at equal distance from previous prime (21431715251) and next prime (21431715257).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431715251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5357928812 + ... + 5357928815.

It is an arithmetic number, because the mean of its divisors is an integer number (8036893221).

Almost surely, 2^21431715254 is an apocalyptic number.

21431715254 is a deficient number, since it is larger than the sum of its proper divisors (10715857630).

21431715254 is a wasteful number, since it uses less digits than its factorization.

21431715254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10715857629.

The product of its digits is 33600, while the sum is 35.

The spelling of 21431715254 in words is "twenty-one billion, four hundred thirty-one million, seven hundred fifteen thousand, two hundred fifty-four".