123776021 has 2 divisors, whose sum is σ = 123776022. Its totient is φ = 123776020.

The previous prime is 123776017. The next prime is 123776033. The reversal of 123776021 is 120677321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 123520996 + 255025 = 11114^2 + 505^2 .

It is an emirp because it is prime and its reverse (120677321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123776021 - 2² = 123776017 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123776071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61888010 + 61888011.

It is an arithmetic number, because the mean of its divisors is an integer number (61888011).

Almost surely, 2^123776021 is an apocalyptic number.

It is an amenable number.

123776021 is a deficient number, since it is larger than the sum of its proper divisors (1).

123776021 is an equidigital number, since it uses as much as digits as its factorization.

123776021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 123776021 is about 11125.4672261438. The cubic root of 123776021 is about 498.3626721677.

The spelling of 123776021 in words is "one hundred twenty-three million, seven hundred seventy-six thousand, twenty-one".