21742774 has 8 divisors (see below), whose sum is σ = 34032240. Its totient is φ = 10398696.

The previous prime is 21742771. The next prime is 21742793. The reversal of 21742774 is 47724712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21742771) 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 3 ways as a sum of consecutive naturals, for example, 236289 + ... + 236380.

It is an arithmetic number, because the mean of its divisors is an integer number (4254030).

Almost surely, 2^21742774 is an apocalyptic number.

21742774 is a deficient number, since it is larger than the sum of its proper divisors (12289466).

21742774 is a wasteful number, since it uses less digits than its factorization.

21742774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472694.

The product of its digits is 21952, while the sum is 34.

The square root of 21742774 is about 4662.9147536707. The cubic root of 21742774 is about 279.1075924407.

The spelling of 21742774 in words is "twenty-one million, seven hundred forty-two thousand, seven hundred seventy-four".