1253916721 has 2 divisors, whose sum is σ = 1253916722. Its totient is φ = 1253916720.

The previous prime is 1253916701. The next prime is 1253916739. The reversal of 1253916721 is 1276193521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1073283121 + 180633600 = 32761^2 + 13440^2 .

It is a cyclic number.

It is not a de Polignac number, because 1253916721 - 2²³ = 1245528113 is a prime.

It is not a weakly prime, because it can be changed into another prime (1253916701) 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 as a sum of consecutive naturals, namely, 626958360 + 626958361.

It is an arithmetic number, because the mean of its divisors is an integer number (626958361).

Almost surely, 2^1253916721 is an apocalyptic number.

It is an amenable number.

1253916721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1253916721 is an equidigital number, since it uses as much as digits as its factorization.

1253916721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 37.

The square root of 1253916721 is about 35410.6865366940. The cubic root of 1253916721 is about 1078.3412812060.

The spelling of 1253916721 in words is "one billion, two hundred fifty-three million, nine hundred sixteen thousand, seven hundred twenty-one".