21540332342 has 16 divisors (see below), whose sum is σ = 32543979552. Its totient is φ = 10692498240.

The previous prime is 21540332339. The next prime is 21540332377. The reversal of 21540332342 is 24323304512.

It is a happy number.

It is a super-2 number, since 2×21540332342² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 234938 + ... + 313490.

It is an arithmetic number, because the mean of its divisors is an integer number (2033998722).

Almost surely, 2^21540332342 is an apocalyptic number.

21540332342 is a deficient number, since it is larger than the sum of its proper divisors (11003647210).

21540332342 is a wasteful number, since it uses less digits than its factorization.

21540332342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79543.

The product of its (nonzero) digits is 17280, while the sum is 29.

Adding to 21540332342 its reverse (24323304512), we get a palindrome (45863636854).

The spelling of 21540332342 in words is "twenty-one billion, five hundred forty million, three hundred thirty-two thousand, three hundred forty-two".