1608690249721 has 4 divisors (see below), whose sum is σ = 1631347858944. Its totient is φ = 1586032640500.

The previous prime is 1608690249637. The next prime is 1608690249743. The reversal of 1608690249721 is 1279420968061.

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 not a de Polignac number, because 1608690249721 - 2¹¹ = 1608690247673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1608690249121) 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, 11328804505 + ... + 11328804646.

It is an arithmetic number, because the mean of its divisors is an integer number (407836964736).

Almost surely, 2^{1608690249721} is an apocalyptic number.

It is an amenable number.

1608690249721 is a deficient number, since it is larger than the sum of its proper divisors (22657609223).

1608690249721 is an equidigital number, since it uses as much as digits as its factorization.

1608690249721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22657609222.

The product of its (nonzero) digits is 2612736, while the sum is 55.

The spelling of 1608690249721 in words is "one trillion, six hundred eight billion, six hundred ninety million, two hundred forty-nine thousand, seven hundred twenty-one".