20309418 has 12 divisors (see below), whose sum is σ = 44003778. Its totient is φ = 6769800.

The previous prime is 20309417. The next prime is 20309431. The reversal of 20309418 is 81490302.

It can be written as a sum of positive squares in only one way, i.e., 15233409 + 5076009 = 3903^2 + 2253^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20309391 and 20309400.

It is not an unprimeable number, because it can be changed into a prime (20309417) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 564133 + ... + 564168.

Almost surely, 2^20309418 is an apocalyptic number.

20309418 is an abundant number, since it is smaller than the sum of its proper divisors (23694360).

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

20309418 is a wasteful number, since it uses less digits than its factorization.

20309418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128309 (or 1128306 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20309418 is about 4506.5971641583. The cubic root of 20309418 is about 272.8344203837.

The spelling of 20309418 in words is "twenty million, three hundred nine thousand, four hundred eighteen".