123511961 has 2 divisors, whose sum is σ = 123511962. Its totient is φ = 123511960.

The previous prime is 123511903. The next prime is 123511963. The reversal of 123511961 is 169115321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83265625 + 40246336 = 9125^2 + 6344^2 .

It is a cyclic number.

It is not a de Polignac number, because 123511961 - 2⁶ = 123511897 is a prime.

Together with 123511963, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123511963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61755980 + 61755981.

It is an arithmetic number, because the mean of its divisors is an integer number (61755981).

Almost surely, 2^123511961 is an apocalyptic number.

It is an amenable number.

123511961 is a deficient number, since it is larger than the sum of its proper divisors (1).

123511961 is an equidigital number, since it uses as much as digits as its factorization.

123511961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 29.

The square root of 123511961 is about 11113.5935232489. The cubic root of 123511961 is about 498.0080225908.

The spelling of 123511961 in words is "one hundred twenty-three million, five hundred eleven thousand, nine hundred sixty-one".