1891419833521 has 9 divisors (see below), whose sum is σ = 1901247322233. Its totient is φ = 1881642904020.

The previous prime is 1891419833503. The next prime is 1891419833531. The reversal of 1891419833521 is 1253389141981.

The square root of 1891419833521 is 1375289.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1891419833521 - 2¹⁹ = 1891419309233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1891419833531) 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 8 ways as a sum of consecutive naturals, for example, 273679056 + ... + 273685966.

Almost surely, 2^{1891419833521} is an apocalyptic number.

1891419833521 is the 1375289-th square number.

1891419833521 is the 687645-th centered octagonal number.

It is an amenable number.

1891419833521 is a deficient number, since it is larger than the sum of its proper divisors (9827488712).

1891419833521 is an frugal number, since it uses more digits than its factorization.

1891419833521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14220 (or 7110 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 55.

The spelling of 1891419833521 in words is "one trillion, eight hundred ninety-one billion, four hundred nineteen million, eight hundred thirty-three thousand, five hundred twenty-one".