2491921873 has 4 divisors (see below), whose sum is σ = 2847910720. Its totient is φ = 2135933028.

The previous prime is 2491921871. The next prime is 2491921879. The reversal of 2491921873 is 3781291942.

It is a happy number.

2491921873 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 3781291942 = 2 ⋅1890645971.

It is a cyclic number.

It is not a de Polignac number, because 2491921873 - 2¹ = 2491921871 is a prime.

It is a super-2 number, since 2×2491921873² = 12419349242271656258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2491921871) 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, 177994413 + ... + 177994426.

It is an arithmetic number, because the mean of its divisors is an integer number (711977680).

Almost surely, 2^2491921873 is an apocalyptic number.

It is an amenable number.

2491921873 is a deficient number, since it is larger than the sum of its proper divisors (355988847).

2491921873 is an equidigital number, since it uses as much as digits as its factorization.

2491921873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355988846.

The product of its digits is 217728, while the sum is 46.

The square root of 2491921873 is about 49919.1533682213. The cubic root of 2491921873 is about 1355.7454036054.

The spelling of 2491921873 in words is "two billion, four hundred ninety-one million, nine hundred twenty-one thousand, eight hundred seventy-three".