20016531 has 16 divisors (see below), whose sum is σ = 31399200. Its totient is φ = 12559104.

The previous prime is 20016523. The next prime is 20016539. The reversal of 20016531 is 13561002.

It is an interprime number because it is at equal distance from previous prime (20016523) and next prime (20016539).

It is not a de Polignac number, because 20016531 - 2³ = 20016523 is a prime.

It is a super-2 number, since 2×20016531² = 801323026547922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20016539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21346 + ... + 22263.

It is an arithmetic number, because the mean of its divisors is an integer number (1962450).

Almost surely, 2^20016531 is an apocalyptic number.

20016531 is a deficient number, since it is larger than the sum of its proper divisors (11382669).

20016531 is a wasteful number, since it uses less digits than its factorization.

20016531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43635 (or 43629 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 20016531 is about 4473.9837952322. The cubic root of 20016531 is about 271.5165277933.

Adding to 20016531 its reverse (13561002), we get a palindrome (33577533).

The spelling of 20016531 in words is "twenty million, sixteen thousand, five hundred thirty-one".