1872633561 has 4 divisors (see below), whose sum is σ = 2496844752. Its totient is φ = 1248422372.

The previous prime is 1872633557. The next prime is 1872633563. The reversal of 1872633561 is 1653362781.

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 1872633561 - 2² = 1872633557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1872633563) 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, 312105591 + ... + 312105596.

It is an arithmetic number, because the mean of its divisors is an integer number (624211188).

Almost surely, 2^1872633561 is an apocalyptic number.

It is an amenable number.

1872633561 is a deficient number, since it is larger than the sum of its proper divisors (624211191).

1872633561 is an equidigital number, since it uses as much as digits as its factorization.

1872633561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624211190.

The product of its digits is 181440, while the sum is 42.

The square root of 1872633561 is about 43273.9362780878. The cubic root of 1872633561 is about 1232.5870507276.

The spelling of 1872633561 in words is "one billion, eight hundred seventy-two million, six hundred thirty-three thousand, five hundred sixty-one".