881211781 has 2 divisors, whose sum is σ = 881211782. Its totient is φ = 881211780.

The previous prime is 881211757. The next prime is 881211791. The reversal of 881211781 is 187112188.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 870545025 + 10666756 = 29505^2 + 3266^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-881211781 is a prime.

It is a super-2 number, since 2×881211781² = 1553068405946383922, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 881211781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (881211731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 440605890 + 440605891.

It is an arithmetic number, because the mean of its divisors is an integer number (440605891).

Almost surely, 2^881211781 is an apocalyptic number.

It is an amenable number.

881211781 is a deficient number, since it is larger than the sum of its proper divisors (1).

881211781 is an equidigital number, since it uses as much as digits as its factorization.

881211781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7168, while the sum is 37.

The square root of 881211781 is about 29685.2114865298. The cubic root of 881211781 is about 958.7236296332.

The spelling of 881211781 in words is "eight hundred eighty-one million, two hundred eleven thousand, seven hundred eighty-one".