125863781 has 2 divisors, whose sum is σ = 125863782. Its totient is φ = 125863780.

The previous prime is 125863769. The next prime is 125863783. The reversal of 125863781 is 187368521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121903681 + 3960100 = 11041^2 + 1990^2 .

It is an emirp because it is prime and its reverse (187368521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 125863781 - 2²² = 121669477 is a prime.

It is a super-2 number, since 2×125863781² = 31683382735231922, which contains 22 as substring.

Together with 125863783, 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 (125863783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62931890 + 62931891.

It is an arithmetic number, because the mean of its divisors is an integer number (62931891).

Almost surely, 2^125863781 is an apocalyptic number.

It is an amenable number.

125863781 is a deficient number, since it is larger than the sum of its proper divisors (1).

125863781 is an equidigital number, since it uses as much as digits as its factorization.

125863781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 41.

The square root of 125863781 is about 11218.9028429700. The cubic root of 125863781 is about 501.1490652751.

The spelling of 125863781 in words is "one hundred twenty-five million, eight hundred sixty-three thousand, seven hundred eighty-one".