21531442030 has 32 divisors (see below), whose sum is σ = 45323334144. Its totient is φ = 7210528416.

The previous prime is 21531442007. The next prime is 21531442061. The reversal of 21531442030 is 3024413512.

It is a junction number, because it is equal to n+sod(n) for n = 21531441986 and 21531442004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3573642 + ... + 3579661.

It is an arithmetic number, because the mean of its divisors is an integer number (1416354192).

Almost surely, 2^21531442030 is an apocalyptic number.

21531442030 is an abundant number, since it is smaller than the sum of its proper divisors (23791892114).

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

21531442030 is a wasteful number, since it uses less digits than its factorization.

21531442030 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7153360.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21531442030 its reverse (3024413512), we get a palindrome (24555855542).

The spelling of 21531442030 in words is "twenty-one billion, five hundred thirty-one million, four hundred forty-two thousand, thirty".