21531222342 has 48 divisors (see below), whose sum is σ = 53323875072. Its totient is φ = 6150800880.

The previous prime is 21531222341. The next prime is 21531222353. The reversal of 21531222342 is 24322213512.

21531222342 is a `hidden beast` number, since 2 + 1 + 5 + 312 + 2 + 2 + 342 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531222341) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1242703 + ... + 1259909.

It is an arithmetic number, because the mean of its divisors is an integer number (1110914064).

Almost surely, 2^21531222342 is an apocalyptic number.

21531222342 is an abundant number, since it is smaller than the sum of its proper divisors (31792652730).

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

21531222342 is a wasteful number, since it uses less digits than its factorization.

21531222342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27153 (or 27150 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

Adding to 21531222342 its reverse (24322213512), we get a palindrome (45853435854).

The spelling of 21531222342 in words is "twenty-one billion, five hundred thirty-one million, two hundred twenty-two thousand, three hundred forty-two".