20951684 has 48 divisors (see below), whose sum is σ = 42357168. Its totient is φ = 8982528.

The previous prime is 20951683. The next prime is 20951713. The reversal of 20951684 is 48615902.

It can be written as a sum of positive squares in 8 ways, for example, as 1149184 + 19802500 = 1072^2 + 4450^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20951683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121022 + ... + 121194.

It is an arithmetic number, because the mean of its divisors is an integer number (882441).

Almost surely, 2^20951684 is an apocalyptic number.

It is an amenable number.

20951684 is an abundant number, since it is smaller than the sum of its proper divisors (21405484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20951684 is a wasteful number, since it uses less digits than its factorization.

20951684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 342 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 20951684 is about 4577.3009514342. The cubic root of 20951684 is about 275.6806675714.

The spelling of 20951684 in words is "twenty million, nine hundred fifty-one thousand, six hundred eighty-four".