125278421 has 2 divisors, whose sum is σ = 125278422. Its totient is φ = 125278420.

The previous prime is 125278399. The next prime is 125278429. The reversal of 125278421 is 124872521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118570321 + 6708100 = 10889^2 + 2590^2 .

It is a cyclic number.

It is not a de Polignac number, because 125278421 - 2⁶ = 125278357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125278429) 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 as a sum of consecutive naturals, namely, 62639210 + 62639211.

It is an arithmetic number, because the mean of its divisors is an integer number (62639211).

Almost surely, 2^125278421 is an apocalyptic number.

It is an amenable number.

125278421 is a deficient number, since it is larger than the sum of its proper divisors (1).

125278421 is an equidigital number, since it uses as much as digits as its factorization.

125278421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8960, while the sum is 32.

The square root of 125278421 is about 11192.7843274138. The cubic root of 125278421 is about 500.3709527201.

The spelling of 125278421 in words is "one hundred twenty-five million, two hundred seventy-eight thousand, four hundred twenty-one".