21148842 has 48 divisors (see below), whose sum is σ = 50010912. Its totient is φ = 5878080.

The previous prime is 21148823. The next prime is 21148847. The reversal of 21148842 is 24884112.

It is not an unprimeable number, because it can be changed into a prime (21148847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 134628 + ... + 134784.

It is an arithmetic number, because the mean of its divisors is an integer number (1041894).

Almost surely, 2^21148842 is an apocalyptic number.

21148842 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21148842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25005456).

21148842 is an abundant number, since it is smaller than the sum of its proper divisors (28862070).

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

21148842 is a wasteful number, since it uses less digits than its factorization.

21148842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 186 counting only the distinct ones).

The product of its digits is 4096, while the sum is 30.

The square root of 21148842 is about 4598.7870139853. The cubic root of 21148842 is about 276.5426992559.

The spelling of 21148842 in words is "twenty-one million, one hundred forty-eight thousand, eight hundred forty-two".