21449942 has 4 divisors (see below), whose sum is σ = 32174916. Its totient is φ = 10724970.

The previous prime is 21449941. The next prime is 21449947. The reversal of 21449942 is 24994412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21449941) 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 as a sum of consecutive naturals, namely, 5362484 + ... + 5362487.

It is an arithmetic number, because the mean of its divisors is an integer number (8043729).

Almost surely, 2^21449942 is an apocalyptic number.

21449942 is a deficient number, since it is larger than the sum of its proper divisors (10724974).

21449942 is a wasteful number, since it uses less digits than its factorization.

21449942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10724973.

The product of its digits is 20736, while the sum is 35.

The square root of 21449942 is about 4631.4082091735. The cubic root of 21449942 is about 277.8489164051.

The spelling of 21449942 in words is "twenty-one million, four hundred forty-nine thousand, nine hundred forty-two".