20280311 has 2 divisors, whose sum is σ = 20280312. Its totient is φ = 20280310.

The previous prime is 20280307. The next prime is 20280347. The reversal of 20280311 is 11308202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20280311 - 2² = 20280307 is a prime.

It is a super-2 number, since 2×20280311² = 822582028513442, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20280311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20280301) 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 as a sum of consecutive naturals, namely, 10140155 + 10140156.

It is an arithmetic number, because the mean of its divisors is an integer number (10140156).

Almost surely, 2^20280311 is an apocalyptic number.

20280311 is a deficient number, since it is larger than the sum of its proper divisors (1).

20280311 is an equidigital number, since it uses as much as digits as its factorization.

20280311 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 20280311 is about 4503.3666295340. The cubic root of 20280311 is about 272.7040180206.

Adding to 20280311 its reverse (11308202), we get a palindrome (31588513).

The spelling of 20280311 in words is "twenty million, two hundred eighty thousand, three hundred eleven".