20321387 has 2 divisors, whose sum is σ = 20321388. Its totient is φ = 20321386.

The previous prime is 20321377. The next prime is 20321401. The reversal of 20321387 is 78312302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20321387 - 2⁸ = 20321131 is a prime.

It is not a weakly prime, because it can be changed into another prime (20321377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10160693 + 10160694.

It is an arithmetic number, because the mean of its divisors is an integer number (10160694).

Almost surely, 2^20321387 is an apocalyptic number.

20321387 is a deficient number, since it is larger than the sum of its proper divisors (1).

20321387 is an equidigital number, since it uses as much as digits as its factorization.

20321387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 20321387 is about 4507.9249106435. The cubic root of 20321387 is about 272.8880065884. Note that the first 3 decimals are identical.

Adding to 20321387 its reverse (78312302), we get a palindrome (98633689).

The spelling of 20321387 in words is "twenty million, three hundred twenty-one thousand, three hundred eighty-seven".