3995887697621 has 2 divisors, whose sum is σ = 3995887697622. Its totient is φ = 3995887697620.

The previous prime is 3995887697609. The next prime is 3995887697741. The reversal of 3995887697621 is 1267967885993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2727022876900 + 1268864820721 = 1651370^2 + 1126439^2 .

It is a cyclic number.

It is not a de Polignac number, because 3995887697621 - 2¹⁰ = 3995887696597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3995887657621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1997943848810 + 1997943848811.

It is an arithmetic number, because the mean of its divisors is an integer number (1997943848811).

Almost surely, 2^{3995887697621} is an apocalyptic number.

It is an amenable number.

3995887697621 is a deficient number, since it is larger than the sum of its proper divisors (1).

3995887697621 is an equidigital number, since it uses as much as digits as its factorization.

3995887697621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2469035520, while the sum is 80.

The spelling of 3995887697621 in words is "three trillion, nine hundred ninety-five billion, eight hundred eighty-seven million, six hundred ninety-seven thousand, six hundred twenty-one".