1125115421 has 2 divisors, whose sum is σ = 1125115422. Its totient is φ = 1125115420.

The previous prime is 1125115391. The next prime is 1125115423. The reversal of 1125115421 is 1245115211.

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., 582691321 + 542424100 = 24139^2 + 23290^2 .

It is a cyclic number.

It is not a de Polignac number, because 1125115421 - 2²⁶ = 1058006557 is a prime.

It is a super-3 number, since 3×1125115421³ (a number of 28 digits) contains 333 as substring.

Together with 1125115423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1125115423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 562557710 + 562557711.

It is an arithmetic number, because the mean of its divisors is an integer number (562557711).

Almost surely, 2^1125115421 is an apocalyptic number.

It is an amenable number.

1125115421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1125115421 is an equidigital number, since it uses as much as digits as its factorization.

1125115421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 400, while the sum is 23.

The square root of 1125115421 is about 33542.7402130476. The cubic root of 1125115421 is about 1040.0774785104.

The spelling of 1125115421 in words is "one billion, one hundred twenty-five million, one hundred fifteen thousand, four hundred twenty-one".