20315387 has 2 divisors, whose sum is σ = 20315388. Its totient is φ = 20315386.

The previous prime is 20315369. The next prime is 20315401. The reversal of 20315387 is 78351302.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20315387 is a prime.

It is not a weakly prime, because it can be changed into another prime (20315287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10157693 + 10157694.

It is an arithmetic number, because the mean of its divisors is an integer number (10157694).

Almost surely, 2^20315387 is an apocalyptic number.

20315387 is a deficient number, since it is larger than the sum of its proper divisors (1).

20315387 is an equidigital number, since it uses as much as digits as its factorization.

20315387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 20315387 is about 4507.2593668437. The cubic root of 20315387 is about 272.8611467222.

Adding to 20315387 its reverse (78351302), we get a palindrome (98666689).

It can be divided in two parts, 20315 and 387, that added together give a palindrome (20702).

The spelling of 20315387 in words is "twenty million, three hundred fifteen thousand, three hundred eighty-seven".