1969626721649 has 4 divisors (see below), whose sum is σ = 2006789490036. Its totient is φ = 1932463953264.

The previous prime is 1969626721633. The next prime is 1969626721687. The reversal of 1969626721649 is 9461276269691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 838264762624 + 1131361959025 = 915568^2 + 1063655^2 .

It is a cyclic number.

It is not a de Polignac number, because 1969626721649 - 2⁴ = 1969626721633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1969626721549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18581384114 + ... + 18581384219.

It is an arithmetic number, because the mean of its divisors is an integer number (501697372509).

Almost surely, 2^{1969626721649} is an apocalyptic number.

It is an amenable number.

1969626721649 is a deficient number, since it is larger than the sum of its proper divisors (37162768387).

1969626721649 is an equidigital number, since it uses as much as digits as its factorization.

1969626721649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37162768386.

The product of its digits is 105815808, while the sum is 68.

The spelling of 1969626721649 in words is "one trillion, nine hundred sixty-nine billion, six hundred twenty-six million, seven hundred twenty-one thousand, six hundred forty-nine".