2191020331 has 4 divisors (see below), whose sum is σ = 2191158432. Its totient is φ = 2190882232.

The previous prime is 2191020329. The next prime is 2191020343. The reversal of 2191020331 is 1330201912.

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

It is a cyclic number.

It is not a de Polignac number, because 2191020331 - 2¹ = 2191020329 is a prime.

It is a super-2 number, since 2×2191020331² = 9601140181710699122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2191020301) 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, 41620 + ... + 78193.

It is an arithmetic number, because the mean of its divisors is an integer number (547789608).

Almost surely, 2^2191020331 is an apocalyptic number.

2191020331 is a deficient number, since it is larger than the sum of its proper divisors (138101).

2191020331 is a wasteful number, since it uses less digits than its factorization.

2191020331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138100.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 2191020331 is about 46808.3361272327. The cubic root of 2191020331 is about 1298.8195064579.

The spelling of 2191020331 in words is "two billion, one hundred ninety-one million, twenty thousand, three hundred thirty-one".