123271781 has 2 divisors, whose sum is σ = 123271782. Its totient is φ = 123271780.

The previous prime is 123271769. The next prime is 123271787. The reversal of 123271781 is 187172321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115240225 + 8031556 = 10735^2 + 2834^2 .

It is a cyclic number.

It is not a de Polignac number, because 123271781 - 2²² = 119077477 is a prime.

It is a super-2 number, since 2×123271781² = 30391863981823922, 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 (123271787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61635890 + 61635891.

It is an arithmetic number, because the mean of its divisors is an integer number (61635891).

Almost surely, 2^123271781 is an apocalyptic number.

It is an amenable number.

123271781 is a deficient number, since it is larger than the sum of its proper divisors (1).

123271781 is an equidigital number, since it uses as much as digits as its factorization.

123271781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4704, while the sum is 32.

The square root of 123271781 is about 11102.7825791556. The cubic root of 123271781 is about 497.6850061489.

The spelling of 123271781 in words is "one hundred twenty-three million, two hundred seventy-one thousand, seven hundred eighty-one".