42780779 has 2 divisors, whose sum is σ = 42780780. Its totient is φ = 42780778.

The previous prime is 42780707. The next prime is 42780781. The reversal of 42780779 is 97708724.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42780779 - 2⁸ = 42780523 is a prime.

Together with 42780781, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42780379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21390389 + 21390390.

It is an arithmetic number, because the mean of its divisors is an integer number (21390390).

Almost surely, 2^42780779 is an apocalyptic number.

42780779 is a deficient number, since it is larger than the sum of its proper divisors (1).

42780779 is an equidigital number, since it uses as much as digits as its factorization.

42780779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 197568, while the sum is 44.

The square root of 42780779 is about 6540.7017207636. The cubic root of 42780779 is about 349.7434282895.

The spelling of 42780779 in words is "forty-two million, seven hundred eighty thousand, seven hundred seventy-nine".