1971812924845 has 4 divisors (see below), whose sum is σ = 2366175509820. Its totient is φ = 1577450339872.

The previous prime is 1971812924821. The next prime is 1971812924897. The reversal of 1971812924845 is 5484292181791.

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

It can be written as a sum of positive squares in 2 ways, for example, as 241762006249 + 1730050918596 = 491693^2 + 1315314^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971812924845 - 2³⁷ = 1834373971373 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197181292480 + ... + 197181292489.

It is an arithmetic number, because the mean of its divisors is an integer number (591543877455).

Almost surely, 2^{1971812924845} is an apocalyptic number.

It is an amenable number.

1971812924845 is a deficient number, since it is larger than the sum of its proper divisors (394362584975).

1971812924845 is an equidigital number, since it uses as much as digits as its factorization.

1971812924845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394362584974.

The product of its digits is 11612160, while the sum is 61.

The spelling of 1971812924845 in words is "one trillion, nine hundred seventy-one billion, eight hundred twelve million, nine hundred twenty-four thousand, eight hundred forty-five".