21449142 has 72 divisors (see below), whose sum is σ = 54983448. Its totient is φ = 5990400.

The previous prime is 21449137. The next prime is 21449143. The reversal of 21449142 is 24194412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21449143) 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 35 ways as a sum of consecutive naturals, for example, 33142 + ... + 33782.

It is an arithmetic number, because the mean of its divisors is an integer number (763659).

Almost surely, 2^21449142 is an apocalyptic number.

21449142 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 21449142, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27491724).

21449142 is an abundant number, since it is smaller than the sum of its proper divisors (33534306).

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

21449142 is a wasteful number, since it uses less digits than its factorization.

21449142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686 (or 670 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21449142 is about 4631.3218415480. The cubic root of 21449142 is about 277.8454621316.

The spelling of 21449142 in words is "twenty-one million, four hundred forty-nine thousand, one hundred forty-two".