351761665721 has 4 divisors (see below), whose sum is σ = 355049158032. Its totient is φ = 348474173412.

The previous prime is 351761665711. The next prime is 351761665751. The reversal of 351761665721 is 127566167153.

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-351761665721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 351761665721.

It is not an unprimeable number, because it can be changed into a prime (351761665711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1643745995 + ... + 1643746208.

It is an arithmetic number, because the mean of its divisors is an integer number (88762289508).

Almost surely, 2^351761665721 is an apocalyptic number.

It is an amenable number.

351761665721 is a deficient number, since it is larger than the sum of its proper divisors (3287492311).

351761665721 is a wasteful number, since it uses less digits than its factorization.

351761665721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3287492310.

The product of its digits is 1587600, while the sum is 50.

The spelling of 351761665721 in words is "three hundred fifty-one billion, seven hundred sixty-one million, six hundred sixty-five thousand, seven hundred twenty-one".