20315121 has 4 divisors (see below), whose sum is σ = 27086832. Its totient is φ = 13543412.

The previous prime is 20315117. The next prime is 20315129. The reversal of 20315121 is 12151302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20315121 - 2² = 20315117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20315121.

It is not an unprimeable number, because it can be changed into a prime (20315129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3385851 + ... + 3385856.

It is an arithmetic number, because the mean of its divisors is an integer number (6771708).

Almost surely, 2^20315121 is an apocalyptic number.

It is an amenable number.

20315121 is a deficient number, since it is larger than the sum of its proper divisors (6771711).

20315121 is an equidigital number, since it uses as much as digits as its factorization.

20315121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6771710.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 20315121 is about 4507.2298587935. The cubic root of 20315121 is about 272.8599558123.

Adding to 20315121 its reverse (12151302), we get a palindrome (32466423).

The spelling of 20315121 in words is "twenty million, three hundred fifteen thousand, one hundred twenty-one".