9991670 has 32 divisors (see below), whose sum is σ = 19535040. Its totient is φ = 3657600.

The previous prime is 9991669. The next prime is 9991673. The reversal of 9991670 is 761999.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991673) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19376 + ... + 19884.

It is an arithmetic number, because the mean of its divisors is an integer number (610470).

Almost surely, 2^9991670 is an apocalyptic number.

9991670 is a deficient number, since it is larger than the sum of its proper divisors (9543370).

9991670 is a wasteful number, since it uses less digits than its factorization.

9991670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680.

The product of its (nonzero) digits is 30618, while the sum is 41.

The square root of 9991670 is about 3160.9602971249. The cubic root of 9991670 is about 215.3836309152.

The spelling of 9991670 in words is "nine million, nine hundred ninety-one thousand, six hundred seventy".