971978994 has 128 divisors (see below), whose sum is σ = 2549568000. Its totient is φ = 274337280.

The previous prime is 971978981. The next prime is 971979017. The reversal of 971978994 is 499879179.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1796364 + ... + 1796904.

It is an arithmetic number, because the mean of its divisors is an integer number (19918500).

Almost surely, 2^971978994 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 971978994, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1274784000).

971978994 is an abundant number, since it is smaller than the sum of its proper divisors (1577589006).

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

971978994 is a wasteful number, since it uses less digits than its factorization.

971978994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670 (or 650 counting only the distinct ones).

The product of its digits is 10287648, while the sum is 63.

The square root of 971978994 is about 31176.5776505376. The cubic root of 971978994 is about 990.5710387853.

The spelling of 971978994 in words is "nine hundred seventy-one million, nine hundred seventy-eight thousand, nine hundred ninety-four".