125521221 has 16 divisors (see below), whose sum is σ = 192006144. Its totient is φ = 71450544.

The previous prime is 125521219. The next prime is 125521223. The reversal of 125521221 is 122125521.

It is an interprime number because it is at equal distance from previous prime (125521219) and next prime (125521223).

It is not a de Polignac number, because 125521221 - 2¹ = 125521219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125521223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5841 + ... + 16886.

It is an arithmetic number, because the mean of its divisors is an integer number (12000384).

Almost surely, 2^125521221 is an apocalyptic number.

It is an amenable number.

125521221 is a deficient number, since it is larger than the sum of its proper divisors (66484923).

125521221 is a wasteful number, since it uses less digits than its factorization.

125521221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23000.

The product of its digits is 400, while the sum is 21.

The square root of 125521221 is about 11203.6253507514. The cubic root of 125521221 is about 500.6939976223.

Adding to 125521221 its reverse (122125521), we get a palindrome (247646742).

The spelling of 125521221 in words is "one hundred twenty-five million, five hundred twenty-one thousand, two hundred twenty-one".