23820781 has 2 divisors, whose sum is σ = 23820782. Its totient is φ = 23820780.

The previous prime is 23820743. The next prime is 23820799. The reversal of 23820781 is 18702832.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23377225 + 443556 = 4835^2 + 666^2 .

It is a cyclic number.

It is not a de Polignac number, because 23820781 - 2¹¹ = 23818733 is a prime.

It is a super-2 number, since 2×23820781² = 1134859214899922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23820701) 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, 11910390 + 11910391.

It is an arithmetic number, because the mean of its divisors is an integer number (11910391).

Almost surely, 2^23820781 is an apocalyptic number.

It is an amenable number.

23820781 is a deficient number, since it is larger than the sum of its proper divisors (1).

23820781 is an equidigital number, since it uses as much as digits as its factorization.

23820781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 23820781 is about 4880.6537471941. The cubic root of 23820781 is about 287.7301235037.

The spelling of 23820781 in words is "twenty-three million, eight hundred twenty thousand, seven hundred eighty-one".