125506813 has 2 divisors, whose sum is σ = 125506814. Its totient is φ = 125506812.

The previous prime is 125506757. The next prime is 125506831. The reversal of 125506813 is 318605521.

Together with next prime (125506831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117223929 + 8282884 = 10827^2 + 2878^2 .

It is a cyclic number.

It is not a de Polignac number, because 125506813 - 2⁹ = 125506301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125506013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62753406 + 62753407.

It is an arithmetic number, because the mean of its divisors is an integer number (62753407).

Almost surely, 2^125506813 is an apocalyptic number.

It is an amenable number.

125506813 is a deficient number, since it is larger than the sum of its proper divisors (1).

125506813 is an equidigital number, since it uses as much as digits as its factorization.

125506813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 125506813 is about 11202.9823261487. The cubic root of 125506813 is about 500.6748394404.

The spelling of 125506813 in words is "one hundred twenty-five million, five hundred six thousand, eight hundred thirteen".