2891185921 has 12 divisors (see below), whose sum is σ = 3132210432. Its totient is φ = 2667493296.

The previous prime is 2891185853. The next prime is 2891185963. The reversal of 2891185921 is 1295811982.

It is a happy number.

It is not a de Polignac number, because 2891185921 - 2³¹ = 743702273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2891185981) 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 11 ways as a sum of consecutive naturals, for example, 647920 + ... + 652366.

It is an arithmetic number, because the mean of its divisors is an integer number (261017536).

Almost surely, 2^2891185921 is an apocalyptic number.

It is an amenable number.

2891185921 is a deficient number, since it is larger than the sum of its proper divisors (241024511).

2891185921 is a wasteful number, since it uses less digits than its factorization.

2891185921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8320 (or 8307 counting only the distinct ones).

The product of its digits is 103680, while the sum is 46.

The square root of 2891185921 is about 53769.7491253214. The cubic root of 2891185921 is about 1424.5969388006.

It can be divided in two parts, 289 and 1185921, that multiplied together give a square (342731169 = 18513²).

The spelling of 2891185921 in words is "two billion, eight hundred ninety-one million, one hundred eighty-five thousand, nine hundred twenty-one".