20811492 has 108 divisors (see below), whose sum is σ = 59793916. Its totient is φ = 6298560.

The previous prime is 20811491. The next prime is 20811521. The reversal of 20811492 is 29411802.

It can be written as a sum of positive squares in 2 ways, for example, as 1679616 + 19131876 = 1296^2 + 4374^2 .

It is a tau number, because it is divible by the number of its divisors (108).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20811491) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 341142 + ... + 341202.

Almost surely, 2^20811492 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 20811492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29896958).

20811492 is an abundant number, since it is smaller than the sum of its proper divisors (38982424).

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

20811492 is an equidigital number, since it uses as much as digits as its factorization.

20811492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 20811492 is about 4561.9614202665. The cubic root of 20811492 is about 275.0644124599.

The spelling of 20811492 in words is "twenty million, eight hundred eleven thousand, four hundred ninety-two".