1561632233 has 4 divisors (see below), whose sum is σ = 1784722560. Its totient is φ = 1338541908.

The previous prime is 1561632229. The next prime is 1561632239. The reversal of 1561632233 is 3322361651.

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.

It is a cyclic number.

It is not a de Polignac number, because 1561632233 - 2² = 1561632229 is a prime.

It is a super-2 number, since 2×1561632233² = 4877390462289132578, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1561632233.

It is not an unprimeable number, because it can be changed into a prime (1561632239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111545153 + ... + 111545166.

It is an arithmetic number, because the mean of its divisors is an integer number (446180640).

Almost surely, 2^1561632233 is an apocalyptic number.

It is an amenable number.

1561632233 is a deficient number, since it is larger than the sum of its proper divisors (223090327).

1561632233 is an equidigital number, since it uses as much as digits as its factorization.

1561632233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223090326.

The product of its digits is 19440, while the sum is 32.

The square root of 1561632233 is about 39517.4927468836. The cubic root of 1561632233 is about 1160.1823516836.

Adding to 1561632233 its reverse (3322361651), we get a palindrome (4883993884).

The spelling of 1561632233 in words is "one billion, five hundred sixty-one million, six hundred thirty-two thousand, two hundred thirty-three".