1832781721 has 9 divisors (see below), whose sum is σ = 1895183199. Its totient is φ = 1772375400.

The previous prime is 1832781719. The next prime is 1832781737. The reversal of 1832781721 is 1271872381.

The square root of 1832781721 is 42811.

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

It can be written as a sum of positive squares in only one way, i.e., 832957321 + 999824400 = 28861^2 + 31620^2 .

It is not a de Polignac number, because 1832781721 - 2¹ = 1832781719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1832781521) 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, 1326451 + ... + 1327831.

It is an arithmetic number, because the mean of its divisors is an integer number (210575911).

Almost surely, 2^1832781721 is an apocalyptic number.

1832781721 is the 42811-st square number.

1832781721 is the 21406-th centered octagonal number.

It is an amenable number.

1832781721 is a deficient number, since it is larger than the sum of its proper divisors (62401478).

1832781721 is an frugal number, since it uses more digits than its factorization.

1832781721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2824 (or 1412 counting only the distinct ones).

The product of its digits is 37632, while the sum is 40.

The cubic root of 1832781721 is about 1223.7806488985.

The spelling of 1832781721 in words is "one billion, eight hundred thirty-two million, seven hundred eighty-one thousand, seven hundred twenty-one".