84045781 has 2 divisors, whose sum is σ = 84045782. Its totient is φ = 84045780.

The previous prime is 84045763. The next prime is 84045803. The reversal of 84045781 is 18754048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81270225 + 2775556 = 9015^2 + 1666^2 .

It is a cyclic number.

It is not a de Polignac number, because 84045781 - 2⁷ = 84045653 is a prime.

It is a super-2 number, since 2×84045781² = 14127386607799922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 84045781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84045751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42022890 + 42022891.

It is an arithmetic number, because the mean of its divisors is an integer number (42022891).

Almost surely, 2^84045781 is an apocalyptic number.

It is an amenable number.

84045781 is a deficient number, since it is larger than the sum of its proper divisors (1).

84045781 is an equidigital number, since it uses as much as digits as its factorization.

84045781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 35840, while the sum is 37.

The square root of 84045781 is about 9167.6486080129. The cubic root of 84045781 is about 438.0314625412.

The spelling of 84045781 in words is "eighty-four million, forty-five thousand, seven hundred eighty-one".