6999987 has 4 divisors (see below), whose sum is σ = 9333320. Its totient is φ = 4666656.

The previous prime is 6999973. The next prime is 6999989. The reversal of 6999987 is 7899996.

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

It is not a de Polignac number, because 6999987 - 2⁸ = 6999731 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6999989) 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, 1166662 + ... + 1166667.

It is an arithmetic number, because the mean of its divisors is an integer number (2333330).

Almost surely, 2^6999987 is an apocalyptic number.

6999987 is a deficient number, since it is larger than the sum of its proper divisors (2333333).

6999987 is a wasteful number, since it uses less digits than its factorization.

6999987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333332.

The product of its digits is 2204496, while the sum is 57.

The square root of 6999987 is about 2645.7488542944. The cubic root of 6999987 is about 191.2929998576.

Subtracting 6999987 from its reverse (7899996), we obtain a palindrome (900009).

The spelling of 6999987 in words is "six million, nine hundred ninety-nine thousand, nine hundred eighty-seven".