21773242 has 16 divisors (see below), whose sum is σ = 34117920. Its totient is φ = 10410768.

The previous prime is 21773239. The next prime is 21773251. The reversal of 21773242 is 24237712.

It is a self number, because there is not a number n which added to its sum of digits gives 21773242.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1873 + ... + 6859.

It is an arithmetic number, because the mean of its divisors is an integer number (2132370).

Almost surely, 2^21773242 is an apocalyptic number.

21773242 is a deficient number, since it is larger than the sum of its proper divisors (12344678).

21773242 is a wasteful number, since it uses less digits than its factorization.

21773242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5085.

The product of its digits is 4704, while the sum is 28.

The square root of 21773242 is about 4666.1806651693. The cubic root of 21773242 is about 279.2379021103.

The spelling of 21773242 in words is "twenty-one million, seven hundred seventy-three thousand, two hundred forty-two".