6989531491 has 4 divisors (see below), whose sum is σ = 6989846400. Its totient is φ = 6989216584.

The previous prime is 6989531447. The next prime is 6989531503. The reversal of 6989531491 is 1941359896.

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 6989531491 - 2¹⁷ = 6989400419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6989531431) 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, 121411 + ... + 169468.

It is an arithmetic number, because the mean of its divisors is an integer number (1747461600).

Almost surely, 2^6989531491 is an apocalyptic number.

6989531491 is a deficient number, since it is larger than the sum of its proper divisors (314909).

6989531491 is a wasteful number, since it uses less digits than its factorization.

6989531491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314908.

The product of its digits is 2099520, while the sum is 55.

The square root of 6989531491 is about 83603.4179385030. The cubic root of 6989531491 is about 1911.9771099941.

The spelling of 6989531491 in words is "six billion, nine hundred eighty-nine million, five hundred thirty-one thousand, four hundred ninety-one".