125405532521 has 2 divisors, whose sum is σ = 125405532522. Its totient is φ = 125405532520.

The previous prime is 125405532431. The next prime is 125405532541. The reversal of 125405532521 is 125235504521.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75493057600 + 49912474921 = 274760^2 + 223411^2 .

It is a cyclic number.

It is not a de Polignac number, because 125405532521 - 2²⁶ = 125338423657 is a prime.

It is not a weakly prime, because it can be changed into another prime (125405532541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62702766260 + 62702766261.

It is an arithmetic number, because the mean of its divisors is an integer number (62702766261).

Almost surely, 2^125405532521 is an apocalyptic number.

It is an amenable number.

125405532521 is a deficient number, since it is larger than the sum of its proper divisors (1).

125405532521 is an equidigital number, since it uses as much as digits as its factorization.

125405532521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60000, while the sum is 35.

The spelling of 125405532521 in words is "one hundred twenty-five billion, four hundred five million, five hundred thirty-two thousand, five hundred twenty-one".