21451223454 has 16 divisors (see below), whose sum is σ = 42907086720. Its totient is φ = 7149634520.

The previous prime is 21451223449. The next prime is 21451223473. The reversal of 21451223454 is 45432215412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131712 + ... + 245459.

It is an arithmetic number, because the mean of its divisors is an integer number (2681692920).

Almost surely, 2^21451223454 is an apocalyptic number.

21451223454 is an abundant number, since it is smaller than the sum of its proper divisors (21455863266).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21451223454 is a wasteful number, since it uses less digits than its factorization.

21451223454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386655.

The product of its digits is 38400, while the sum is 33.

Adding to 21451223454 its reverse (45432215412), we get a palindrome (66883438866).

The spelling of 21451223454 in words is "twenty-one billion, four hundred fifty-one million, two hundred twenty-three thousand, four hundred fifty-four".