123557881 has 2 divisors, whose sum is σ = 123557882. Its totient is φ = 123557880.

The previous prime is 123557869. The next prime is 123557891. The reversal of 123557881 is 188755321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123010281 + 547600 = 11091^2 + 740^2 .

It is a cyclic number.

It is not a de Polignac number, because 123557881 - 2¹³ = 123549689 is a prime.

It is a super-2 number, since 2×123557881² = 30533099914420322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (123557801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61778940 + 61778941.

It is an arithmetic number, because the mean of its divisors is an integer number (61778941).

Almost surely, 2^123557881 is an apocalyptic number.

It is an amenable number.

123557881 is a deficient number, since it is larger than the sum of its proper divisors (1).

123557881 is an equidigital number, since it uses as much as digits as its factorization.

123557881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 67200, while the sum is 40.

The square root of 123557881 is about 11115.6592696970. The cubic root of 123557881 is about 498.0697323900.

The spelling of 123557881 in words is "one hundred twenty-three million, five hundred fifty-seven thousand, eight hundred eighty-one".