21940244 has 6 divisors (see below), whose sum is σ = 38395434. Its totient is φ = 10970120.

The previous prime is 21940241. The next prime is 21940267. The reversal of 21940244 is 44204912.

It can be written as a sum of positive squares in only one way, i.e., 18835600 + 3104644 = 4340^2 + 1762^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21940241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2742527 + ... + 2742534.

It is an arithmetic number, because the mean of its divisors is an integer number (6399239).

Almost surely, 2^21940244 is an apocalyptic number.

It is an amenable number.

21940244 is a deficient number, since it is larger than the sum of its proper divisors (16455190).

21940244 is a wasteful number, since it uses less digits than its factorization.

21940244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5485065 (or 5485063 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 21940244 is about 4684.0414174087. The cubic root of 21940244 is about 279.9500080816.

The spelling of 21940244 in words is "twenty-one million, nine hundred forty thousand, two hundred forty-four".