21767242 has 16 divisors (see below), whose sum is σ = 39510720. Its totient is φ = 8779968.

The previous prime is 21767237. The next prime is 21767243. The reversal of 21767242 is 24276712.

It is not an unprimeable number, because it can be changed into a prime (21767243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45492 + ... + 45967.

It is an arithmetic number, because the mean of its divisors is an integer number (2469420).

Almost surely, 2^21767242 is an apocalyptic number.

21767242 is a deficient number, since it is larger than the sum of its proper divisors (17743478).

21767242 is a wasteful number, since it uses less digits than its factorization.

21767242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91485.

The product of its digits is 9408, while the sum is 31.

The square root of 21767242 is about 4665.5376967719. The cubic root of 21767242 is about 279.2122501145.

The spelling of 21767242 in words is "twenty-one million, seven hundred sixty-seven thousand, two hundred forty-two".