21582086 has 4 divisors (see below), whose sum is σ = 32373132. Its totient is φ = 10791042.

The previous prime is 21582049. The next prime is 21582097. The reversal of 21582086 is 68028512.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21582086² = 931572872222792, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5395520 + ... + 5395523.

It is an arithmetic number, because the mean of its divisors is an integer number (8093283).

Almost surely, 2^21582086 is an apocalyptic number.

21582086 is a deficient number, since it is larger than the sum of its proper divisors (10791046).

21582086 is a wasteful number, since it uses less digits than its factorization.

21582086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10791045.

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 21582086 is about 4645.6523761470. The cubic root of 21582086 is about 278.4183185171.

The spelling of 21582086 in words is "twenty-one million, five hundred eighty-two thousand, eighty-six".