84573781 has 2 divisors, whose sum is σ = 84573782. Its totient is φ = 84573780.

The previous prime is 84573761. The next prime is 84573787. The reversal of 84573781 is 18737548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51969681 + 32604100 = 7209^2 + 5710^2 .

It is a cyclic number.

It is not a de Polignac number, because 84573781 - 2¹¹ = 84571733 is a prime.

It is a super-2 number, since 2×84573781² = 14305448865271922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84573787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42286890 + 42286891.

It is an arithmetic number, because the mean of its divisors is an integer number (42286891).

Almost surely, 2^84573781 is an apocalyptic number.

It is an amenable number.

84573781 is a deficient number, since it is larger than the sum of its proper divisors (1).

84573781 is an equidigital number, since it uses as much as digits as its factorization.

84573781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 188160, while the sum is 43.

The square root of 84573781 is about 9196.4004371276. The cubic root of 84573781 is about 438.9468286223.

The spelling of 84573781 in words is "eighty-four million, five hundred seventy-three thousand, seven hundred eighty-one".