2085172921 has 4 divisors (see below), whose sum is σ = 2245570852. Its totient is φ = 1924774992.

The previous prime is 2085172909. The next prime is 2085172937. The reversal of 2085172921 is 1292715802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 390615696 + 1694557225 = 19764^2 + 41165^2 .

It is a cyclic number.

It is not a de Polignac number, because 2085172921 - 2⁵ = 2085172889 is a prime.

It is a super-2 number, since 2×2085172921² = 8695892220943344482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2085175921) 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, 80198946 + ... + 80198971.

It is an arithmetic number, because the mean of its divisors is an integer number (561392713).

Almost surely, 2^2085172921 is an apocalyptic number.

It is an amenable number.

2085172921 is a deficient number, since it is larger than the sum of its proper divisors (160397931).

2085172921 is a wasteful number, since it uses less digits than its factorization.

2085172921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160397930.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 2085172921 is about 45663.6936854653. The cubic root of 2085172921 is about 1277.5581949662.

The spelling of 2085172921 in words is "two billion, eighty-five million, one hundred seventy-two thousand, nine hundred twenty-one".