125521645 has 4 divisors (see below), whose sum is σ = 150625980. Its totient is φ = 100417312.

The previous prime is 125521637. The next prime is 125521667. The reversal of 125521645 is 546125521.

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 93644329 + 31877316 = 9677^2 + 5646^2 .

It is a cyclic number.

It is not a de Polignac number, because 125521645 - 2³ = 125521637 is a prime.

It is a super-3 number, since 3×125521645³ (a number of 25 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 12552160 + ... + 12552169.

It is an arithmetic number, because the mean of its divisors is an integer number (37656495).

Almost surely, 2^125521645 is an apocalyptic number.

It is an amenable number.

125521645 is a deficient number, since it is larger than the sum of its proper divisors (25104335).

125521645 is an equidigital number, since it uses as much as digits as its factorization.

125521645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25104334.

The product of its digits is 12000, while the sum is 31.

The square root of 125521645 is about 11203.6442731818. The cubic root of 125521645 is about 500.6945613889.

It can be divided in two parts, 125 and 521645, that multiplied together give a square (65205625 = 8075²).

The spelling of 125521645 in words is "one hundred twenty-five million, five hundred twenty-one thousand, six hundred forty-five".