6989978 has 4 divisors (see below), whose sum is σ = 10484970. Its totient is φ = 3494988.

The previous prime is 6989963. The next prime is 6989987. The reversal of 6989978 is 8799896.

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

It can be written as a sum of positive squares in only one way, i.e., 6775609 + 214369 = 2603^2 + 463^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1747493 + ... + 1747496.

Almost surely, 2^6989978 is an apocalyptic number.

6989978 is a deficient number, since it is larger than the sum of its proper divisors (3494992).

6989978 is a wasteful number, since it uses less digits than its factorization.

6989978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3494991.

The product of its digits is 1959552, while the sum is 56.

The square root of 6989978 is about 2643.8566526951. The cubic root of 6989978 is about 191.2017823110.

The spelling of 6989978 in words is "six million, nine hundred eighty-nine thousand, nine hundred seventy-eight".