1252721999 has 2 divisors, whose sum is σ = 1252722000. Its totient is φ = 1252721998.

The previous prime is 1252721989. The next prime is 1252722001. The reversal of 1252721999 is 9991272521.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1252721999 is a prime.

Together with 1252722001, 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 (1252721909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 626360999 + 626361000.

It is an arithmetic number, because the mean of its divisors is an integer number (626361000).

Almost surely, 2^1252721999 is an apocalyptic number.

1252721999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1252721999 is an equidigital number, since it uses as much as digits as its factorization.

1252721999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 47.

The square root of 1252721999 is about 35393.8130045351. The cubic root of 1252721999 is about 1077.9986940114.

The spelling of 1252721999 in words is "one billion, two hundred fifty-two million, seven hundred twenty-one thousand, nine hundred ninety-nine".