125201656421 has 2 divisors, whose sum is σ = 125201656422. Its totient is φ = 125201656420.

The previous prime is 125201656403. The next prime is 125201656427. The reversal of 125201656421 is 124656102521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124354264321 + 847392100 = 352639^2 + 29110^2 .

It is a cyclic number.

It is not a de Polignac number, because 125201656421 - 2³⁰ = 124127914597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125201656427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62600828210 + 62600828211.

It is an arithmetic number, because the mean of its divisors is an integer number (62600828211).

Almost surely, 2^125201656421 is an apocalyptic number.

It is an amenable number.

125201656421 is a deficient number, since it is larger than the sum of its proper divisors (1).

125201656421 is an equidigital number, since it uses as much as digits as its factorization.

125201656421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28800, while the sum is 35.

Adding to 125201656421 its reverse (124656102521), we get a palindrome (249857758942).

The spelling of 125201656421 in words is "one hundred twenty-five billion, two hundred one million, six hundred fifty-six thousand, four hundred twenty-one".