191978970 has 48 divisors (see below), whose sum is σ = 476163360. Its totient is φ = 49535520.

The previous prime is 191978957. The next prime is 191978971. The reversal of 191978970 is 79879191.

It is not an unprimeable number, because it can be changed into a prime (191978971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25501 + ... + 32159.

It is an arithmetic number, because the mean of its divisors is an integer number (9920070).

Almost surely, 2^191978970 is an apocalyptic number.

191978970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 191978970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238081680).

191978970 is an abundant number, since it is smaller than the sum of its proper divisors (284184390).

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

191978970 is a wasteful number, since it uses less digits than its factorization.

191978970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6731 (or 6700 counting only the distinct ones).

The product of its (nonzero) digits is 285768, while the sum is 51.

The square root of 191978970 is about 13855.6475850102. The cubic root of 191978970 is about 576.8787645008.

The spelling of 191978970 in words is "one hundred ninety-one million, nine hundred seventy-eight thousand, nine hundred seventy".