125555566 has 4 divisors (see below), whose sum is σ = 188333352. Its totient is φ = 62777782.

The previous prime is 125555531. The next prime is 125555567. The reversal of 125555566 is 665555521.

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

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125555567) 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, 31388890 + ... + 31388893.

It is an arithmetic number, because the mean of its divisors is an integer number (47083338).

Almost surely, 2^125555566 is an apocalyptic number.

125555566 is a deficient number, since it is larger than the sum of its proper divisors (62777786).

125555566 is an equidigital number, since it uses as much as digits as its factorization.

125555566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62777785.

The product of its digits is 225000, while the sum is 40.

The square root of 125555566 is about 11205.1580087030. The cubic root of 125555566 is about 500.7396599335.

The spelling of 125555566 in words is "one hundred twenty-five million, five hundred fifty-five thousand, five hundred sixty-six".