6991121033 has 4 divisors (see below), whose sum is σ = 7528899588. Its totient is φ = 6453342480.

The previous prime is 6991120957. The next prime is 6991121083. The reversal of 6991121033 is 3301211996.

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 2476356169 + 4514764864 = 49763^2 + 67192^2 .

It is not a de Polignac number, because 6991121033 - 2¹⁴ = 6991104649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6991120984 and 6991121002.

It is not an unprimeable number, because it can be changed into a prime (6991121083) 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, 268889258 + ... + 268889283.

It is an arithmetic number, because the mean of its divisors is an integer number (1882224897).

Almost surely, 2^6991121033 is an apocalyptic number.

It is an amenable number.

6991121033 is a deficient number, since it is larger than the sum of its proper divisors (537778555).

6991121033 is a wasteful number, since it uses less digits than its factorization.

6991121033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537778554.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 6991121033 is about 83612.9238395596. The cubic root of 6991121033 is about 1912.1220380466.

The spelling of 6991121033 in words is "six billion, nine hundred ninety-one million, one hundred twenty-one thousand, thirty-three".