42780869 has 2 divisors, whose sum is σ = 42780870. Its totient is φ = 42780868.

The previous prime is 42780863. The next prime is 42780919. The reversal of 42780869 is 96808724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38316100 + 4464769 = 6190^2 + 2113^2 .

It is a cyclic number.

It is not a de Polignac number, because 42780869 - 2⁸ = 42780613 is a prime.

It is a super-2 number, since 2×42780869² = 3660405504790322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42780863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21390434 + 21390435.

It is an arithmetic number, because the mean of its divisors is an integer number (21390435).

Almost surely, 2^42780869 is an apocalyptic number.

It is an amenable number.

42780869 is a deficient number, since it is larger than the sum of its proper divisors (1).

42780869 is an equidigital number, since it uses as much as digits as its factorization.

42780869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 44.

The square root of 42780869 is about 6540.7086007557. The cubic root of 42780869 is about 349.7436735467.

The spelling of 42780869 in words is "forty-two million, seven hundred eighty thousand, eight hundred sixty-nine".