1911969121 has 4 divisors (see below), whose sum is σ = 1930532032. Its totient is φ = 1893406212.

The previous prime is 1911969091. The next prime is 1911969127. The reversal of 1911969121 is 1219691191.

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-1911969121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1911969127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9281301 + ... + 9281506.

It is an arithmetic number, because the mean of its divisors is an integer number (482633008).

Almost surely, 2^1911969121 is an apocalyptic number.

It is an amenable number.

1911969121 is a deficient number, since it is larger than the sum of its proper divisors (18562911).

1911969121 is a wasteful number, since it uses less digits than its factorization.

1911969121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18562910.

The product of its digits is 8748, while the sum is 40.

The square root of 1911969121 is about 43726.0691235789. The cubic root of 1911969121 is about 1241.1576772984.

The spelling of 1911969121 in words is "one billion, nine hundred eleven million, nine hundred sixty-nine thousand, one hundred twenty-one".