20813015 has 8 divisors (see below), whose sum is σ = 26444880. Its totient is φ = 15670912.

The previous prime is 20813003. The next prime is 20813021. The reversal of 20813015 is 51031802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20813015 - 2¹² = 20808919 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122345 + ... + 122514.

It is an arithmetic number, because the mean of its divisors is an integer number (3305610).

Almost surely, 2^20813015 is an apocalyptic number.

20813015 is a deficient number, since it is larger than the sum of its proper divisors (5631865).

20813015 is a wasteful number, since it uses less digits than its factorization.

20813015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244881.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 20813015 is about 4562.1283410268. The cubic root of 20813015 is about 275.0711221003.

Adding to 20813015 its reverse (51031802), we get a palindrome (71844817).

The spelling of 20813015 in words is "twenty million, eight hundred thirteen thousand, fifteen".