163231227781 has 2 divisors, whose sum is σ = 163231227782. Its totient is φ = 163231227780.

The previous prime is 163231227749. The next prime is 163231227799. The reversal of 163231227781 is 187722132361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149800735681 + 13430492100 = 387041^2 + 115890^2 .

It is a cyclic number.

It is not a de Polignac number, because 163231227781 - 2⁵ = 163231227749 is a prime.

It is a super-2 number, since 2×163231227781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163231227701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81615613890 + 81615613891.

It is an arithmetic number, because the mean of its divisors is an integer number (81615613891).

Almost surely, 2^163231227781 is an apocalyptic number.

It is an amenable number.

163231227781 is a deficient number, since it is larger than the sum of its proper divisors (1).

163231227781 is an equidigital number, since it uses as much as digits as its factorization.

163231227781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 169344, while the sum is 43.

The spelling of 163231227781 in words is "one hundred sixty-three billion, two hundred thirty-one million, two hundred twenty-seven thousand, seven hundred eighty-one".