1969789121 has 2 divisors, whose sum is σ = 1969789122. Its totient is φ = 1969789120.

The previous prime is 1969789061. The next prime is 1969789141. The reversal of 1969789121 is 1219879691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1369000000 + 600789121 = 37000^2 + 24511^2 .

It is an emirp because it is prime and its reverse (1219879691) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1969789121 is a prime.

It is not a weakly prime, because it can be changed into another prime (1969789141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 984894560 + 984894561.

It is an arithmetic number, because the mean of its divisors is an integer number (984894561).

Almost surely, 2^1969789121 is an apocalyptic number.

It is an amenable number.

1969789121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1969789121 is an equidigital number, since it uses as much as digits as its factorization.

1969789121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 53.

The square root of 1969789121 is about 44382.3063956798. The cubic root of 1969789121 is about 1253.5449496420.

The spelling of 1969789121 in words is "one billion, nine hundred sixty-nine million, seven hundred eighty-nine thousand, one hundred twenty-one".