830073721 has 9 divisors (see below), whose sum is σ = 849496431. Its totient is φ = 811087272.

The previous prime is 830073689. The next prime is 830073733. The reversal of 830073721 is 127370038.

The square root of 830073721 is 28811.

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., 2706025 + 827367696 = 1645^2 + 28764^2 .

It is not a de Polignac number, because 830073721 - 2⁵ = 830073689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (830073791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1353811 + ... + 1354423.

Almost surely, 2^830073721 is an apocalyptic number.

830073721 is the 28811-st square number.

830073721 is the 14406-th centered octagonal number.

It is an amenable number.

830073721 is a deficient number, since it is larger than the sum of its proper divisors (19422710).

830073721 is an frugal number, since it uses more digits than its factorization.

830073721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1320 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 31.

The cubic root of 830073721 is about 939.8074605650.

Multiplying 830073721 by its product of nonzero digits (7056), we get a square (5857000175376 = 2420124²).

The spelling of 830073721 in words is "eight hundred thirty million, seventy-three thousand, seven hundred twenty-one".