21513221342 has 16 divisors (see below), whose sum is σ = 33456278400. Its totient is φ = 10364159520.

The previous prime is 21513221341. The next prime is 21513221347. The reversal of 21513221342 is 24312231512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513221341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 743417 + ... + 771812.

It is an arithmetic number, because the mean of its divisors is an integer number (2091017400).

Almost surely, 2^21513221342 is an apocalyptic number.

21513221342 is a deficient number, since it is larger than the sum of its proper divisors (11943057058).

21513221342 is a wasteful number, since it uses less digits than its factorization.

21513221342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1515491.

The product of its digits is 2880, while the sum is 26.

Adding to 21513221342 its reverse (24312231512), we get a palindrome (45825452854).

The spelling of 21513221342 in words is "twenty-one billion, five hundred thirteen million, two hundred twenty-one thousand, three hundred forty-two".