21531542004444 has 96 divisors (see below), whose sum is σ = 51661326024000. Its totient is φ = 6975512893440.

The previous prime is 21531542004437. The next prime is 21531542004451. The reversal of 21531542004444 is 44440024513512.

It is an interprime number because it is at equal distance from previous prime (21531542004437) and next prime (21531542004451).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 914317582 + ... + 914341130.

It is an arithmetic number, because the mean of its divisors is an integer number (538138812750).

Almost surely, 2^{21531542004444} is an apocalyptic number.

It is an amenable number.

21531542004444 is an abundant number, since it is smaller than the sum of its proper divisors (30129784019556).

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

21531542004444 is a wasteful number, since it uses less digits than its factorization.

21531542004444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30583 (or 30581 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 39.

Adding to 21531542004444 its reverse (44440024513512), we get a palindrome (65971566517956).

The spelling of 21531542004444 in words is "twenty-one trillion, five hundred thirty-one billion, five hundred forty-two million, four thousand, four hundred forty-four".