20995812 has 36 divisors (see below), whose sum is σ = 53677260. Its totient is φ = 6918912.

The previous prime is 20995787. The next prime is 20995831. The reversal of 20995812 is 21859902.

It can be written as a sum of positive squares in 2 ways, for example, as 5503716 + 15492096 = 2346^2 + 3936^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 73 + ... + 6480.

It is an arithmetic number, because the mean of its divisors is an integer number (1491035).

Almost surely, 2^20995812 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20995812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26838630).

20995812 is an abundant number, since it is smaller than the sum of its proper divisors (32681448).

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

20995812 is a wasteful number, since it uses less digits than its factorization.

20995812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6652 (or 6647 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 20995812 is about 4582.1187239093. The cubic root of 20995812 is about 275.8740761419.

The spelling of 20995812 in words is "twenty million, nine hundred ninety-five thousand, eight hundred twelve".