1253773561 has 2 divisors, whose sum is σ = 1253773562. Its totient is φ = 1253773560.

The previous prime is 1253773553. The next prime is 1253773567. The reversal of 1253773561 is 1653773521.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1240377961 + 13395600 = 35219^2 + 3660^2 .

It is an emirp because it is prime and its reverse (1653773521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1253773561 - 2³ = 1253773553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1253773567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 626886780 + 626886781.

It is an arithmetic number, because the mean of its divisors is an integer number (626886781).

Almost surely, 2^1253773561 is an apocalyptic number.

It is an amenable number.

1253773561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1253773561 is an equidigital number, since it uses as much as digits as its factorization.

1253773561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 132300, while the sum is 40.

The square root of 1253773561 is about 35408.6650553223. The cubic root of 1253773561 is about 1078.3002414754.

Subtracting from 1253773561 its sum of digits (40), we obtain a palindrome (1253773521).

The spelling of 1253773561 in words is "one billion, two hundred fifty-three million, seven hundred seventy-three thousand, five hundred sixty-one".