125666381 has 2 divisors, whose sum is σ = 125666382. Its totient is φ = 125666380.

The previous prime is 125666377. The next prime is 125666383. The reversal of 125666381 is 183666521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96138025 + 29528356 = 9805^2 + 5434^2 .

It is a cyclic number.

It is not a de Polignac number, because 125666381 - 2² = 125666377 is a prime.

It is a super-2 number, since 2×125666381² = 31584078627274322, which contains 22 as substring.

Together with 125666383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125666383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62833190 + 62833191.

It is an arithmetic number, because the mean of its divisors is an integer number (62833191).

Almost surely, 2^125666381 is an apocalyptic number.

It is an amenable number.

125666381 is a deficient number, since it is larger than the sum of its proper divisors (1).

125666381 is an equidigital number, since it uses as much as digits as its factorization.

125666381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 38.

The square root of 125666381 is about 11210.1017390566. The cubic root of 125666381 is about 500.8869337667.

The spelling of 125666381 in words is "one hundred twenty-five million, six hundred sixty-six thousand, three hundred eighty-one".