20131516 has 12 divisors (see below), whose sum is σ = 35442288. Its totient is φ = 10005152.

The previous prime is 20131513. The next prime is 20131523. The reversal of 20131516 is 61513102.

It is a junction number, because it is equal to n+sod(n) for n = 20131493 and 20131502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14401 + ... + 15736.

It is an arithmetic number, because the mean of its divisors is an integer number (2953524).

Almost surely, 2^20131516 is an apocalyptic number.

It is an amenable number.

20131516 is a deficient number, since it is larger than the sum of its proper divisors (15310772).

20131516 is a wasteful number, since it uses less digits than its factorization.

20131516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30308 (or 30306 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 20131516 is about 4486.8157974225. The cubic root of 20131516 is about 272.0354444871.

Adding to 20131516 its reverse (61513102), we get a palindrome (81644618).

The spelling of 20131516 in words is "twenty million, one hundred thirty-one thousand, five hundred sixteen".