125705521 has 2 divisors, whose sum is σ = 125705522. Its totient is φ = 125705520.

The previous prime is 125705519. The next prime is 125705533. The reversal of 125705521 is 125507521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122323600 + 3381921 = 11060^2 + 1839^2 .

It is a cyclic number.

It is not a de Polignac number, because 125705521 - 2¹ = 125705519 is a prime.

Together with 125705519, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 125705521.

It is not a weakly prime, because it can be changed into another prime (125705561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62852760 + 62852761.

It is an arithmetic number, because the mean of its divisors is an integer number (62852761).

Almost surely, 2^125705521 is an apocalyptic number.

It is an amenable number.

125705521 is a deficient number, since it is larger than the sum of its proper divisors (1).

125705521 is an equidigital number, since it uses as much as digits as its factorization.

125705521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3500, while the sum is 28.

The square root of 125705521 is about 11211.8473500133. The cubic root of 125705521 is about 500.9389303825.

The spelling of 125705521 in words is "one hundred twenty-five million, seven hundred five thousand, five hundred twenty-one".