840772181 has 2 divisors, whose sum is σ = 840772182. Its totient is φ = 840772180.

The previous prime is 840772157. The next prime is 840772187. The reversal of 840772181 is 181277048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674233156 + 166539025 = 25966^2 + 12905^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840772181 is a prime.

It is a super-2 number, since 2×840772181² = 1413795720686993522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840772187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420386090 + 420386091.

It is an arithmetic number, because the mean of its divisors is an integer number (420386091).

Almost surely, 2^840772181 is an apocalyptic number.

It is an amenable number.

840772181 is a deficient number, since it is larger than the sum of its proper divisors (1).

840772181 is an equidigital number, since it uses as much as digits as its factorization.

840772181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25088, while the sum is 38.

The square root of 840772181 is about 28996.0718201621. The cubic root of 840772181 is about 943.8278276474.

The spelling of 840772181 in words is "eight hundred forty million, seven hundred seventy-two thousand, one hundred eighty-one".