21580474 has 8 divisors (see below), whose sum is σ = 32668020. Its totient is φ = 10691136.

The previous prime is 21580451. The next prime is 21580477. The reversal of 21580474 is 47408512.

It can be written as a sum of positive squares in 2 ways, for example, as 18429849 + 3150625 = 4293^2 + 1775^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21580477) 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, 49279 + ... + 49714.

Almost surely, 2^21580474 is an apocalyptic number.

21580474 is a deficient number, since it is larger than the sum of its proper divisors (11087546).

21580474 is a wasteful number, since it uses less digits than its factorization.

21580474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99104.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 21580474 is about 4645.4788773602. The cubic root of 21580474 is about 278.4113865102.

Adding to 21580474 its reverse (47408512), we get a palindrome (68988986).

The spelling of 21580474 in words is "twenty-one million, five hundred eighty thousand, four hundred seventy-four".