42873781 has 2 divisors, whose sum is σ = 42873782. Its totient is φ = 42873780.

The previous prime is 42873773. The next prime is 42873791. The reversal of 42873781 is 18737824.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42693156 + 180625 = 6534^2 + 425^2 .

It is a cyclic number.

It is not a de Polignac number, because 42873781 - 2³ = 42873773 is a prime.

It is a super-2 number, since 2×42873781² = 3676322194471922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42873731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21436890 + 21436891.

It is an arithmetic number, because the mean of its divisors is an integer number (21436891).

Almost surely, 2^42873781 is an apocalyptic number.

It is an amenable number.

42873781 is a deficient number, since it is larger than the sum of its proper divisors (1).

42873781 is an equidigital number, since it uses as much as digits as its factorization.

42873781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 40.

The square root of 42873781 is about 6547.8073429202. The cubic root of 42873781 is about 349.9966829618.

The spelling of 42873781 in words is "forty-two million, eight hundred seventy-three thousand, seven hundred eighty-one".