1561252133 has 4 divisors (see below), whose sum is σ = 1784288160. Its totient is φ = 1338216108.

The previous prime is 1561252109. The next prime is 1561252139. The reversal of 1561252133 is 3312521651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3312521651 = 41 ⋅80793211.

It is a cyclic number.

It is not a de Polignac number, because 1561252133 - 2¹² = 1561248037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1561252096 and 1561252105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561252139) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111518003 + ... + 111518016.

It is an arithmetic number, because the mean of its divisors is an integer number (446072040).

Almost surely, 2^1561252133 is an apocalyptic number.

It is an amenable number.

1561252133 is a deficient number, since it is larger than the sum of its proper divisors (223036027).

1561252133 is an equidigital number, since it uses as much as digits as its factorization.

1561252133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223036026.

The product of its digits is 5400, while the sum is 29.

The square root of 1561252133 is about 39512.6831916032. The cubic root of 1561252133 is about 1160.0882149025.

Adding to 1561252133 its reverse (3312521651), we get a palindrome (4873773784).

The spelling of 1561252133 in words is "one billion, five hundred sixty-one million, two hundred fifty-two thousand, one hundred thirty-three".