1971945616 has 20 divisors (see below), whose sum is σ = 3825279100. Its totient is φ = 984776832.

The previous prime is 1971945593. The next prime is 1971945629. The reversal of 1971945616 is 6165491791.

It can be written as a sum of positive squares in 2 ways, for example, as 1156272016 + 815673600 = 34004^2 + 28560^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1971945616.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61071 + ... + 87598.

It is an arithmetic number, because the mean of its divisors is an integer number (191263955).

Almost surely, 2^1971945616 is an apocalyptic number.

1971945616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1971945616 is a deficient number, since it is larger than the sum of its proper divisors (1853333484).

1971945616 is a wasteful number, since it uses less digits than its factorization.

1971945616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149506 (or 149500 counting only the distinct ones).

The product of its digits is 408240, while the sum is 49.

The square root of 1971945616 is about 44406.5942850834. The cubic root of 1971945616 is about 1254.0022367512.

The spelling of 1971945616 in words is "one billion, nine hundred seventy-one million, nine hundred forty-five thousand, six hundred sixteen".