20815151 has 12 divisors (see below), whose sum is σ = 24384600. Its totient is φ = 17715600.

The previous prime is 20815129. The next prime is 20815153. The reversal of 20815151 is 15151802.

It is not a de Polignac number, because 20815151 - 2⁶ = 20815087 is a prime.

It is a super-2 number, since 2×20815151² = 866541022305602, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20815153) 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, 5876 + ... + 8726.

It is an arithmetic number, because the mean of its divisors is an integer number (2032050).

Almost surely, 2^20815151 is an apocalyptic number.

20815151 is a deficient number, since it is larger than the sum of its proper divisors (3569449).

20815151 is a wasteful number, since it uses less digits than its factorization.

20815151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3014 (or 3007 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 20815151 is about 4562.3624362823. The cubic root of 20815151 is about 275.0805317864.

Adding to 20815151 its reverse (15151802), we get a palindrome (35966953).

The spelling of 20815151 in words is "twenty million, eight hundred fifteen thousand, one hundred fifty-one".