125147821 has 2 divisors, whose sum is σ = 125147822. Its totient is φ = 125147820.

The previous prime is 125147819. The next prime is 125147833. The reversal of 125147821 is 128741521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69122596 + 56025225 = 8314^2 + 7485^2 .

It is a cyclic number.

It is not a de Polignac number, because 125147821 - 2¹ = 125147819 is a prime.

Together with 125147819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125147881) 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, 62573910 + 62573911.

It is an arithmetic number, because the mean of its divisors is an integer number (62573911).

Almost surely, 2^125147821 is an apocalyptic number.

It is an amenable number.

125147821 is a deficient number, since it is larger than the sum of its proper divisors (1).

125147821 is an equidigital number, since it uses as much as digits as its factorization.

125147821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 31.

The square root of 125147821 is about 11186.9486903266. The cubic root of 125147821 is about 500.1970170251.

The spelling of 125147821 in words is "one hundred twenty-five million, one hundred forty-seven thousand, eight hundred twenty-one".