20280761 has 2 divisors, whose sum is σ = 20280762. Its totient is φ = 20280760.

The previous prime is 20280751. The next prime is 20280763. The reversal of 20280761 is 16708202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16000000 + 4280761 = 4000^2 + 2069^2 .

It is a cyclic number.

It is not a de Polignac number, because 20280761 - 2¹⁸ = 20018617 is a prime.

It is a super-2 number, since 2×20280761² = 822618533478242, which contains 22 as substring.

Together with 20280763, it forms a pair of twin primes.

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 20280761.

It is not a weakly prime, because it can be changed into another prime (20280763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10140380 + 10140381.

It is an arithmetic number, because the mean of its divisors is an integer number (10140381).

Almost surely, 2^20280761 is an apocalyptic number.

It is an amenable number.

20280761 is a deficient number, since it is larger than the sum of its proper divisors (1).

20280761 is an equidigital number, since it uses as much as digits as its factorization.

20280761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20280761 is about 4503.4165918778. The cubic root of 20280761 is about 272.7060350163.

Adding to 20280761 its reverse (16708202), we get a palindrome (36988963).

The spelling of 20280761 in words is "twenty million, two hundred eighty thousand, seven hundred sixty-one".