21774736 has 10 divisors (see below), whose sum is σ = 42188582. Its totient is φ = 10887360.

The previous prime is 21774733. The next prime is 21774749. The reversal of 21774736 is 63747712.

It can be written as a sum of positive squares in only one way, i.e., 21344400 + 430336 = 4620^2 + 656^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21774695 and 21774704.

It is not an unprimeable number, because it can be changed into a prime (21774733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 680445 + ... + 680476.

Almost surely, 2^21774736 is an apocalyptic number.

It is an amenable number.

21774736 is a deficient number, since it is larger than the sum of its proper divisors (20413846).

21774736 is a wasteful number, since it uses less digits than its factorization.

21774736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360929 (or 1360923 counting only the distinct ones).

The product of its digits is 49392, while the sum is 37.

The square root of 21774736 is about 4666.3407505239. The cubic root of 21774736 is about 279.2442887244.

The spelling of 21774736 in words is "twenty-one million, seven hundred seventy-four thousand, seven hundred thirty-six".