21740804 has 24 divisors (see below), whose sum is σ = 38813880. Its totient is φ = 10653696.

The previous prime is 21740801. The next prime is 21740833. The reversal of 21740804 is 40804712.

It can be written as a sum of positive squares in 4 ways, for example, as 8065600 + 13675204 = 2840^2 + 3698^2 .

It is not an unprimeable number, because it can be changed into a prime (21740801) 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, 52952 + ... + 53360.

It is an arithmetic number, because the mean of its divisors is an integer number (1617245).

Almost surely, 2^21740804 is an apocalyptic number.

It is an amenable number.

21740804 is a deficient number, since it is larger than the sum of its proper divisors (17073076).

21740804 is a wasteful number, since it uses less digits than its factorization.

21740804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647 (or 645 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 21740804 is about 4662.7035076230. The cubic root of 21740804 is about 279.0991626889.

The spelling of 21740804 in words is "twenty-one million, seven hundred forty thousand, eight hundred four".