21344454631 has 4 divisors (see below), whose sum is σ = 22467847000. Its totient is φ = 20221062264.

The previous prime is 21344454619. The next prime is 21344454667. The reversal of 21344454631 is 13645444312.

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 21344454631 - 2¹³ = 21344446439 is a prime.

It is a super-2 number, since 2×21344454631² (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 (21344454731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561696156 + ... + 561696193.

It is an arithmetic number, because the mean of its divisors is an integer number (5616961750).

Almost surely, 2^21344454631 is an apocalyptic number.

21344454631 is a deficient number, since it is larger than the sum of its proper divisors (1123392369).

21344454631 is a wasteful number, since it uses less digits than its factorization.

21344454631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1123392368.

The product of its digits is 138240, while the sum is 37.

Adding to 21344454631 its reverse (13645444312), we get a palindrome (34989898943).

The spelling of 21344454631 in words is "twenty-one billion, three hundred forty-four million, four hundred fifty-four thousand, six hundred thirty-one".