1971085979 has 4 divisors (see below), whose sum is σ = 1972083960. Its totient is φ = 1970088000.

The previous prime is 1971085889. The next prime is 1971086009. The reversal of 1971085979 is 9795801791.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1971085979 is a prime.

It is a super-2 number, since 2×1971085979² = 7770359873220776882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1971085279) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496022 + ... + 499979.

It is an arithmetic number, because the mean of its divisors is an integer number (493020990).

Almost surely, 2^1971085979 is an apocalyptic number.

1971085979 is a deficient number, since it is larger than the sum of its proper divisors (997981).

1971085979 is an equidigital number, since it uses as much as digits as its factorization.

1971085979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997980.

The product of its (nonzero) digits is 1428840, while the sum is 56.

The square root of 1971085979 is about 44396.9140706874. The cubic root of 1971085979 is about 1253.8199897708.

The spelling of 1971085979 in words is "one billion, nine hundred seventy-one million, eighty-five thousand, nine hundred seventy-nine".