21673748 has 12 divisors (see below), whose sum is σ = 38854452. Its totient is φ = 10572480.

The previous prime is 21673741. The next prime is 21673753. The reversal of 21673748 is 84737612.

It can be written as a sum of positive squares in 2 ways, for example, as 5769604 + 15904144 = 2402^2 + 3988^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21673741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65915 + ... + 66242.

It is an arithmetic number, because the mean of its divisors is an integer number (3237871).

Almost surely, 2^21673748 is an apocalyptic number.

It is an amenable number.

21673748 is a deficient number, since it is larger than the sum of its proper divisors (17180704).

21673748 is a wasteful number, since it uses less digits than its factorization.

21673748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132202 (or 132200 counting only the distinct ones).

The product of its digits is 56448, while the sum is 38.

The square root of 21673748 is about 4655.5072763341. The cubic root of 21673748 is about 278.8119217340.

The spelling of 21673748 in words is "twenty-one million, six hundred seventy-three thousand, seven hundred forty-eight".