21320023542 has 32 divisors (see below), whose sum is σ = 43080021504. Its totient is φ = 7033404000.

The previous prime is 21320023531. The next prime is 21320023547. The reversal of 21320023542 is 24532002312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320023547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1852867 + ... + 1864337.

It is an arithmetic number, because the mean of its divisors is an integer number (1346250672).

Almost surely, 2^21320023542 is an apocalyptic number.

21320023542 is an abundant number, since it is smaller than the sum of its proper divisors (21759997962).

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

21320023542 is a wasteful number, since it uses less digits than its factorization.

21320023542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14644.

The product of its (nonzero) digits is 2880, while the sum is 24.

Adding to 21320023542 its reverse (24532002312), we get a palindrome (45852025854).

The spelling of 21320023542 in words is "twenty-one billion, three hundred twenty million, twenty-three thousand, five hundred forty-two".