125204561 has 4 divisors (see below), whose sum is σ = 125724324. Its totient is φ = 124684800.

The previous prime is 125204543. The next prime is 125204621. The reversal of 125204561 is 165402521.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 85451536 + 39753025 = 9244^2 + 6305^2 .

It is a cyclic number.

It is not a de Polignac number, because 125204561 - 2²² = 121010257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 125204561.

It is not an unprimeable number, because it can be changed into a prime (125204161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 259520 + ... + 260001.

It is an arithmetic number, because the mean of its divisors is an integer number (31431081).

Almost surely, 2^125204561 is an apocalyptic number.

It is an amenable number.

125204561 is a deficient number, since it is larger than the sum of its proper divisors (519763).

125204561 is an equidigital number, since it uses as much as digits as its factorization.

125204561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519762.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 125204561 is about 11189.4843938405. The cubic root of 125204561 is about 500.2725993522.

The spelling of 125204561 in words is "one hundred twenty-five million, two hundred four thousand, five hundred sixty-one".