6990591 has 4 divisors (see below), whose sum is σ = 9320792. Its totient is φ = 4660392.

The previous prime is 6990563. The next prime is 6990611. The reversal of 6990591 is 1950996.

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

It is not a de Polignac number, because 6990591 - 2⁵ = 6990559 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

6990591 is a lucky number.

It is a plaindrome in base 4 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6990691) 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, 1165096 + ... + 1165101.

It is an arithmetic number, because the mean of its divisors is an integer number (2330198).

Almost surely, 2^6990591 is an apocalyptic number.

6990591 is a deficient number, since it is larger than the sum of its proper divisors (2330201).

6990591 is a wasteful number, since it uses less digits than its factorization.

6990591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2330200.

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 6990591 is about 2643.9725792829. The cubic root of 6990591 is about 191.2073714209.

It can be divided in two parts, 69905 and 91, that added together give a palindrome (69996).

The spelling of 6990591 in words is "six million, nine hundred ninety thousand, five hundred ninety-one".