1257389321 has 2 divisors, whose sum is σ = 1257389322. Its totient is φ = 1257389320.

The previous prime is 1257389267. The next prime is 1257389381. The reversal of 1257389321 is 1239837521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1129699321 + 127690000 = 33611^2 + 11300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1257389321 is a prime.

It is not a weakly prime, because it can be changed into another prime (1257389381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628694660 + 628694661.

It is an arithmetic number, because the mean of its divisors is an integer number (628694661).

Almost surely, 2^1257389321 is an apocalyptic number.

It is an amenable number.

1257389321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1257389321 is an equidigital number, since it uses as much as digits as its factorization.

1257389321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 41.

The square root of 1257389321 is about 35459.6858559125. The cubic root of 1257389321 is about 1079.3358173308.

The spelling of 1257389321 in words is "one billion, two hundred fifty-seven million, three hundred eighty-nine thousand, three hundred twenty-one".