123211350891989 has 2 divisors, whose sum is σ = 123211350891990. Its totient is φ = 123211350891988.

The previous prime is 123211350891869. The next prime is 123211350892009. The reversal of 123211350891989 is 989198053112321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68987891751025 + 54223459140964 = 8305895^2 + 7363658^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123211350891989 is a prime.

It is a super-2 number, since 2×123211350891989² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123211350891389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61605675445994 + 61605675445995.

It is an arithmetic number, because the mean of its divisors is an integer number (61605675445995).

Almost surely, 2^{123211350891989} is an apocalyptic number.

It is an amenable number.

123211350891989 is a deficient number, since it is larger than the sum of its proper divisors (1).

123211350891989 is an equidigital number, since it uses as much as digits as its factorization.

123211350891989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8398080, while the sum is 62.

The spelling of 123211350891989 in words is "one hundred twenty-three trillion, two hundred eleven billion, three hundred fifty million, eight hundred ninety-one thousand, nine hundred eighty-nine".