125551813 has 4 divisors (see below), whose sum is σ = 125585100. Its totient is φ = 125518528.

The previous prime is 125551807. The next prime is 125551837. The reversal of 125551813 is 318155521.

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 64352484 + 61199329 = 8022^2 + 7823^2 .

It is a cyclic number.

It is not a de Polignac number, because 125551813 - 2⁵ = 125551781 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 (125551513) 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, 10138 + ... + 18811.

It is an arithmetic number, because the mean of its divisors is an integer number (31396275).

Almost surely, 2^125551813 is an apocalyptic number.

It is an amenable number.

125551813 is a deficient number, since it is larger than the sum of its proper divisors (33287).

125551813 is an equidigital number, since it uses as much as digits as its factorization.

125551813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33286.

The product of its digits is 6000, while the sum is 31.

The square root of 125551813 is about 11204.9905399335. The cubic root of 125551813 is about 500.7346706560.

The spelling of 125551813 in words is "one hundred twenty-five million, five hundred fifty-one thousand, eight hundred thirteen".