20403516 has 48 divisors (see below), whose sum is σ = 55448064. Its totient is φ = 5718336.

The previous prime is 20403491. The next prime is 20403521. The reversal of 20403516 is 61530402.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20403492 and 20403501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2161 + ... + 6743.

It is an arithmetic number, because the mean of its divisors is an integer number (1155168).

Almost surely, 2^20403516 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 20403516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27724032).

20403516 is an abundant number, since it is smaller than the sum of its proper divisors (35044548).

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

20403516 is a wasteful number, since it uses less digits than its factorization.

20403516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4650 (or 4648 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20403516 is about 4517.0251272270. The cubic root of 20403516 is about 273.2551385815.

Adding to 20403516 its reverse (61530402), we get a palindrome (81933918).

The spelling of 20403516 in words is "twenty million, four hundred three thousand, five hundred sixteen".