7829387721 has 16 divisors (see below), whose sum is σ = 11701744320. Its totient is φ = 5173398720.

The previous prime is 7829387677. The next prime is 7829387767. The reversal of 7829387721 is 1277839287.

It is not a de Polignac number, because 7829387721 - 2¹¹ = 7829385673 is a prime.

It is a super-2 number, since 2×7829387721² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7829387221) 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 15 ways as a sum of consecutive naturals, for example, 1280035 + ... + 1286136.

It is an arithmetic number, because the mean of its divisors is an integer number (731359020).

Almost surely, 2^7829387721 is an apocalyptic number.

It is an amenable number.

7829387721 is a deficient number, since it is larger than the sum of its proper divisors (3872356599).

7829387721 is a wasteful number, since it uses less digits than its factorization.

7829387721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2566293 (or 2566287 counting only the distinct ones).

The product of its digits is 2370816, while the sum is 54.

The square root of 7829387721 is about 88483.8274545128. The cubic root of 7829387721 is about 1985.6800239326.

The spelling of 7829387721 in words is "seven billion, eight hundred twenty-nine million, three hundred eighty-seven thousand, seven hundred twenty-one".