1231122989 has 2 divisors, whose sum is σ = 1231122990. Its totient is φ = 1231122988.

The previous prime is 1231122973. The next prime is 1231123039. The reversal of 1231122989 is 9892211321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1152942025 + 78180964 = 33955^2 + 8842^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231122989 - 2⁴ = 1231122973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231122289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615561494 + 615561495.

It is an arithmetic number, because the mean of its divisors is an integer number (615561495).

Almost surely, 2^1231122989 is an apocalyptic number.

It is an amenable number.

1231122989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231122989 is an equidigital number, since it uses as much as digits as its factorization.

1231122989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 38.

The square root of 1231122989 is about 35087.3622405561. The cubic root of 1231122989 is about 1071.7672455084.

The spelling of 1231122989 in words is "one billion, two hundred thirty-one million, one hundred twenty-two thousand, nine hundred eighty-nine".