1275025021 has 2 divisors, whose sum is σ = 1275025022. Its totient is φ = 1275025020.

The previous prime is 1275025019. The next prime is 1275025043. The reversal of 1275025021 is 1205205721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 866419225 + 408605796 = 29435^2 + 20214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1275025021 - 2¹ = 1275025019 is a prime.

Together with 1275025019, 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 (1275025061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 637512510 + 637512511.

It is an arithmetic number, because the mean of its divisors is an integer number (637512511).

Almost surely, 2^1275025021 is an apocalyptic number.

It is an amenable number.

1275025021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1275025021 is an equidigital number, since it uses as much as digits as its factorization.

1275025021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 1275025021 is about 35707.4925050752. The cubic root of 1275025021 is about 1084.3585357963.

The spelling of 1275025021 in words is "one billion, two hundred seventy-five million, twenty-five thousand, twenty-one".