20851682 has 4 divisors (see below), whose sum is σ = 31277526. Its totient is φ = 10425840.

The previous prime is 20851681. The next prime is 20851687. The reversal of 20851682 is 28615802.

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., 19456921 + 1394761 = 4411^2 + 1181^2 .

It is not an unprimeable number, because it can be changed into a prime (20851681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5212919 + ... + 5212922.

Almost surely, 2^20851682 is an apocalyptic number.

20851682 is a deficient number, since it is larger than the sum of its proper divisors (10425844).

20851682 is a wasteful number, since it uses less digits than its factorization.

20851682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10425843.

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

The square root of 20851682 is about 4566.3641992290. The cubic root of 20851682 is about 275.2413616538.

The spelling of 20851682 in words is "twenty million, eight hundred fifty-one thousand, six hundred eighty-two".