21542158242 has 24 divisors (see below), whose sum is σ = 50917829040. Its totient is φ = 6527926680.

The previous prime is 21542158237. The next prime is 21542158273. The reversal of 21542158242 is 24285124512.

21542158242 is a `hidden beast` number, since 2 + 1 + 54 + 21 + 582 + 4 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21542158197 and 21542158206.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 54399192 + ... + 54399587.

It is an arithmetic number, because the mean of its divisors is an integer number (2121576210).

Almost surely, 2^21542158242 is an apocalyptic number.

21542158242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21542158242 is an abundant number, since it is smaller than the sum of its proper divisors (29375670798).

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

21542158242 is a wasteful number, since it uses less digits than its factorization.

21542158242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108798798 (or 108798795 counting only the distinct ones).

The product of its digits is 51200, while the sum is 36.

The spelling of 21542158242 in words is "twenty-one billion, five hundred forty-two million, one hundred fifty-eight thousand, two hundred forty-two".