1252721 has 2 divisors, whose sum is σ = 1252722. Its totient is φ = 1252720.

The previous prime is 1252717. The next prime is 1252729. The reversal of 1252721 is 1272521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 790321 + 462400 = 889^2 + 680^2 .

It is a cyclic number.

It is not a de Polignac number, because 1252721 - 2² = 1252717 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 1252693 and 1252702.

It is not a weakly prime, because it can be changed into another prime (1252729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 626360 + 626361.

It is an arithmetic number, because the mean of its divisors is an integer number (626361).

2^1252721 is an apocalyptic number.

It is an amenable number.

1252721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1252721 is an equidigital number, since it uses as much as digits as its factorization.

1252721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 280, while the sum is 20.

The square root of 1252721 is about 1119.2501954434. The cubic root of 1252721 is about 107.7998407456.

The spelling of 1252721 in words is "one million, two hundred fifty-two thousand, seven hundred twenty-one".