3991625691425 has 6 divisors (see below), whose sum is σ = 4949615857398. Its totient is φ = 3193300553120.

The previous prime is 3991625691413. The next prime is 3991625691439. The reversal of 3991625691425 is 5241965261993.

It can be written as a sum of positive squares in 3 ways, for example, as 145826224384 + 3845799467041 = 381872^2 + 1961071^2 .

It is a de Polignac number, because none of the positive numbers 2^k-3991625691425 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 79832513804 + ... + 79832513853.

It is an arithmetic number, because the mean of its divisors is an integer number (824935976233).

Almost surely, 2^{3991625691425} is an apocalyptic number.

It is an amenable number.

3991625691425 is a deficient number, since it is larger than the sum of its proper divisors (957990165973).

3991625691425 is a wasteful number, since it uses less digits than its factorization.

3991625691425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159665027667 (or 159665027662 counting only the distinct ones).

The product of its digits is 31492800, while the sum is 62.

The spelling of 3991625691425 in words is "three trillion, nine hundred ninety-one billion, six hundred twenty-five million, six hundred ninety-one thousand, four hundred twenty-five".