1921851329 has 2 divisors, whose sum is σ = 1921851330. Its totient is φ = 1921851328.

The previous prime is 1921851317. The next prime is 1921851389. The reversal of 1921851329 is 9231581291.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1877228929 + 44622400 = 43327^2 + 6680^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921851329 - 2⁴ = 1921851313 is a prime.

It is not a weakly prime, because it can be changed into another prime (1921851389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960925664 + 960925665.

It is an arithmetic number, because the mean of its divisors is an integer number (960925665).

Almost surely, 2^1921851329 is an apocalyptic number.

It is an amenable number.

1921851329 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921851329 is an equidigital number, since it uses as much as digits as its factorization.

1921851329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 41.

The square root of 1921851329 is about 43838.9248157388. The cubic root of 1921851329 is about 1243.2923538896.

The spelling of 1921851329 in words is "one billion, nine hundred twenty-one million, eight hundred fifty-one thousand, three hundred twenty-nine".