125521111 has 4 divisors (see below), whose sum is σ = 126158472. Its totient is φ = 124883752.

The previous prime is 125521073. The next prime is 125521141. The reversal of 125521111 is 111125521.

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

It is a cyclic number.

It is not a de Polignac number, because 125521111 - 2¹⁵ = 125488343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125521141) 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, 318385 + ... + 318778.

It is an arithmetic number, because the mean of its divisors is an integer number (31539618).

Almost surely, 2^125521111 is an apocalyptic number.

125521111 is a deficient number, since it is larger than the sum of its proper divisors (637361).

125521111 is an equidigital number, since it uses as much as digits as its factorization.

125521111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637360.

The product of its digits is 100, while the sum is 19.

The square root of 125521111 is about 11203.6204416251. The cubic root of 125521111 is about 500.6938513619.

Adding to 125521111 its reverse (111125521), we get a palindrome (236646632).

It can be divided in two parts, 1255 and 21111, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 125521111 in words is "one hundred twenty-five million, five hundred twenty-one thousand, one hundred eleven".