125491977649 has 2 divisors, whose sum is σ = 125491977650. Its totient is φ = 125491977648.

The previous prime is 125491977631. The next prime is 125491977673. The reversal of 125491977649 is 946779194521.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75021210000 + 50470767649 = 273900^2 + 224657^2 .

It is an emirp because it is prime and its reverse (946779194521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 125491977649 - 2¹¹ = 125491975601 is a prime.

It is not a weakly prime, because it can be changed into another prime (125491947649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62745988824 + 62745988825.

It is an arithmetic number, because the mean of its divisors is an integer number (62745988825).

Almost surely, 2^125491977649 is an apocalyptic number.

It is an amenable number.

125491977649 is a deficient number, since it is larger than the sum of its proper divisors (1).

125491977649 is an equidigital number, since it uses as much as digits as its factorization.

125491977649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34292160, while the sum is 64.

The spelling of 125491977649 in words is "one hundred twenty-five billion, four hundred ninety-one million, nine hundred seventy-seven thousand, six hundred forty-nine".