1829691780921 has 9 divisors (see below), whose sum is σ = 2642893989541. Its totient is φ = 1219791815292.

The previous prime is 1829691780887. The next prime is 1829691780929. The reversal of 1829691780921 is 1290871969281.

The square root of 1829691780921 is 1352661.

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

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 1829691780921 - 2⁹ = 1829691780409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1829691780929) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3832540 + ... + 4283426.

Almost surely, 2^{1829691780921} is an apocalyptic number.

1829691780921 is the 1352661-st square number.

1829691780921 is the 676331-st centered octagonal number.

It is an amenable number.

1829691780921 is a deficient number, since it is larger than the sum of its proper divisors (813202208620).

1829691780921 is an frugal number, since it uses more digits than its factorization.

1829691780921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901780 (or 450890 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 63.

The spelling of 1829691780921 in words is "one trillion, eight hundred twenty-nine billion, six hundred ninety-one million, seven hundred eighty thousand, nine hundred twenty-one".