1253689621 has 2 divisors, whose sum is σ = 1253689622. Its totient is φ = 1253689620.

The previous prime is 1253689601. The next prime is 1253689637. The reversal of 1253689621 is 1269863521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1241787121 + 11902500 = 35239^2 + 3450^2 .

It is a cyclic number.

It is not a de Polignac number, because 1253689621 - 2¹¹ = 1253687573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1253689601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 626844810 + 626844811.

It is an arithmetic number, because the mean of its divisors is an integer number (626844811).

Almost surely, 2^1253689621 is an apocalyptic number.

It is an amenable number.

1253689621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1253689621 is an equidigital number, since it uses as much as digits as its factorization.

1253689621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 43.

The square root of 1253689621 is about 35407.4797323955. The cubic root of 1253689621 is about 1078.2761769114.

The spelling of 1253689621 in words is "one billion, two hundred fifty-three million, six hundred eighty-nine thousand, six hundred twenty-one".