6690978 has 64 divisors (see below), whose sum is σ = 17571840. Its totient is φ = 1846800.

The previous prime is 6690973. The next prime is 6690989. The reversal of 6690978 is 8790966.

It is not an unprimeable number, because it can be changed into a prime (6690973) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11433 + ... + 12003.

It is an arithmetic number, because the mean of its divisors is an integer number (274560).

Almost surely, 2^6690978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6690978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8785920).

6690978 is an abundant number, since it is smaller than the sum of its proper divisors (10880862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6690978 is a wasteful number, since it uses less digits than its factorization.

6690978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 614 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 6690978 is about 2586.6924826890. The cubic root of 6690978 is about 188.4357066486.

The spelling of 6690978 in words is "six million, six hundred ninety thousand, nine hundred seventy-eight".