21842746 has 4 divisors (see below), whose sum is σ = 32764122. Its totient is φ = 10921372.

The previous prime is 21842719. The next prime is 21842749. The reversal of 21842746 is 64724812.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 18584721 + 3258025 = 4311^2 + 1805^2 .

It is a pancake number, because a pancake can be divided into 21842746 parts by 6609 straight cuts.

It is not an unprimeable number, because it can be changed into a prime (21842749) 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, 5460685 + ... + 5460688.

Almost surely, 2^21842746 is an apocalyptic number.

21842746 is a deficient number, since it is larger than the sum of its proper divisors (10921376).

21842746 is a wasteful number, since it uses less digits than its factorization.

21842746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10921375.

The product of its digits is 21504, while the sum is 34.

The square root of 21842746 is about 4673.6223638630. The cubic root of 21842746 is about 279.5347119329.

The spelling of 21842746 in words is "twenty-one million, eight hundred forty-two thousand, seven hundred forty-six".