2131661683649 has 4 divisors (see below), whose sum is σ = 2131681736640. Its totient is φ = 2131641630660.

The previous prime is 2131661683589. The next prime is 2131661683721. The reversal of 2131661683649 is 9463861661312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2131661683649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2131661683594 and 2131661683603.

It is not an unprimeable number, because it can be changed into a prime (2131661613649) 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, 9866189 + ... + 10079930.

It is an arithmetic number, because the mean of its divisors is an integer number (532920434160).

Almost surely, 2^{2131661683649} is an apocalyptic number.

It is an amenable number.

2131661683649 is a deficient number, since it is larger than the sum of its proper divisors (20052991).

2131661683649 is a wasteful number, since it uses less digits than its factorization.

2131661683649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20052990.

The product of its digits is 6718464, while the sum is 56.

The spelling of 2131661683649 in words is "two trillion, one hundred thirty-one billion, six hundred sixty-one million, six hundred eighty-three thousand, six hundred forty-nine".