20406312 has 48 divisors (see below), whose sum is σ = 55692000. Its totient is φ = 6749856.

The previous prime is 20406311. The next prime is 20406329. The reversal of 20406312 is 21360402.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20406311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8989 + ... + 11027.

It is an arithmetic number, because the mean of its divisors is an integer number (1160250).

Almost surely, 2^20406312 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 20406312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27846000).

20406312 is an abundant number, since it is smaller than the sum of its proper divisors (35285688).

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

20406312 is a wasteful number, since it uses less digits than its factorization.

20406312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2190 (or 2183 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 20406312 is about 4517.3346123572. The cubic root of 20406312 is about 273.2676198694.

Adding to 20406312 its reverse (21360402), we get a palindrome (41766714).

The spelling of 20406312 in words is "twenty million, four hundred six thousand, three hundred twelve".