20809682 has 4 divisors (see below), whose sum is σ = 31214526. Its totient is φ = 10404840.

The previous prime is 20809669. The next prime is 20809699. The reversal of 20809682 is 28690802.

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

It can be written as a sum of positive squares in only one way, i.e., 20693401 + 116281 = 4549^2 + 341^2 .

It is a super-2 number, since 2×20809682² = 866085729882248, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5202419 + ... + 5202422.

Almost surely, 2^20809682 is an apocalyptic number.

20809682 is a deficient number, since it is larger than the sum of its proper divisors (10404844).

20809682 is a wasteful number, since it uses less digits than its factorization.

20809682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10404843.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 20809682 is about 4561.7630363709. The cubic root of 20809682 is about 275.0564380033.

The spelling of 20809682 in words is "twenty million, eight hundred nine thousand, six hundred eighty-two".