1242125251 has 4 divisors (see below), whose sum is σ = 1242474552. Its totient is φ = 1241775952.

The previous prime is 1242125233. The next prime is 1242125257. The reversal of 1242125251 is 1525212421.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1242125251 - 2⁷ = 1242125123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242125257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169261 + ... + 176446.

It is an arithmetic number, because the mean of its divisors is an integer number (310618638).

Almost surely, 2^1242125251 is an apocalyptic number.

1242125251 is a deficient number, since it is larger than the sum of its proper divisors (349301).

1242125251 is an equidigital number, since it uses as much as digits as its factorization.

1242125251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349300.

The product of its digits is 1600, while the sum is 25.

The square root of 1242125251 is about 35243.7973408088. The cubic root of 1242125251 is about 1074.9504937721.

Adding to 1242125251 its reverse (1525212421), we get a palindrome (2767337672).

The spelling of 1242125251 in words is "one billion, two hundred forty-two million, one hundred twenty-five thousand, two hundred fifty-one".