21908142 has 12 divisors (see below), whose sum is σ = 47467680. Its totient is φ = 7302708.

The previous prime is 21908141. The next prime is 21908147. The reversal of 21908142 is 24180912.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21908141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 608542 + ... + 608577.

It is an arithmetic number, because the mean of its divisors is an integer number (3955640).

Almost surely, 2^21908142 is an apocalyptic number.

21908142 is an abundant number, since it is smaller than the sum of its proper divisors (25559538).

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

21908142 is a wasteful number, since it uses less digits than its factorization.

21908142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217127 (or 1217124 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 21908142 is about 4680.6134213370. The cubic root of 21908142 is about 279.8134045897.

The spelling of 21908142 in words is "twenty-one million, nine hundred eight thousand, one hundred forty-two".