42798781 has 2 divisors, whose sum is σ = 42798782. Its totient is φ = 42798780.

The previous prime is 42798737. The next prime is 42798787. The reversal of 42798781 is 18789724.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42693156 + 105625 = 6534^2 + 325^2 .

It is a cyclic number.

It is not a de Polignac number, because 42798781 - 2⁹ = 42798269 is a prime.

It is a super-2 number, since 2×42798781² = 3663471310171922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42798787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21399390 + 21399391.

It is an arithmetic number, because the mean of its divisors is an integer number (21399391).

Almost surely, 2^42798781 is an apocalyptic number.

It is an amenable number.

42798781 is a deficient number, since it is larger than the sum of its proper divisors (1).

42798781 is an equidigital number, since it uses as much as digits as its factorization.

42798781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 225792, while the sum is 46.

The square root of 42798781 is about 6542.0777280616. The cubic root of 42798781 is about 349.7924783413.

The spelling of 42798781 in words is "forty-two million, seven hundred ninety-eight thousand, seven hundred eighty-one".