42780138977 has 2 divisors, whose sum is σ = 42780138978. Its totient is φ = 42780138976.

The previous prime is 42780138967. The next prime is 42780139007. The reversal of 42780138977 is 77983108724.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27373371601 + 15406767376 = 165449^2 + 124124^2 .

It is a cyclic number.

It is not a de Polignac number, because 42780138977 - 2¹⁸ = 42779876833 is a prime.

It is not a weakly prime, because it can be changed into another prime (42780138967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21390069488 + 21390069489.

It is an arithmetic number, because the mean of its divisors is an integer number (21390069489).

Almost surely, 2^42780138977 is an apocalyptic number.

It is an amenable number.

42780138977 is a deficient number, since it is larger than the sum of its proper divisors (1).

42780138977 is an equidigital number, since it uses as much as digits as its factorization.

42780138977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4741632, while the sum is 56.

The spelling of 42780138977 in words is "forty-two billion, seven hundred eighty million, one hundred thirty-eight thousand, nine hundred seventy-seven".