125016781 has 4 divisors (see below), whose sum is σ = 127924192. Its totient is φ = 122109372.

The previous prime is 125016743. The next prime is 125016797. The reversal of 125016781 is 187610521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 125016781 - 2¹¹ = 125014733 is a prime.

It is a super-2 number, since 2×125016781² = 31258391063203922, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125016721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1453641 + ... + 1453726.

It is an arithmetic number, because the mean of its divisors is an integer number (31981048).

Almost surely, 2^125016781 is an apocalyptic number.

It is an amenable number.

125016781 is a deficient number, since it is larger than the sum of its proper divisors (2907411).

125016781 is an equidigital number, since it uses as much as digits as its factorization.

125016781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2907410.

The product of its (nonzero) digits is 3360, while the sum is 31.

The square root of 125016781 is about 11181.0903314480. The cubic root of 125016781 is about 500.0223736655.

The spelling of 125016781 in words is "one hundred twenty-five million, sixteen thousand, seven hundred eighty-one".