767728721 has 8 divisors (see below), whose sum is σ = 814020480. Its totient is φ = 721562688.

The previous prime is 767728711. The next prime is 767728729. The reversal of 767728721 is 127827767.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 767728721 - 2⁶ = 767728657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (767728729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18701 + ... + 43418.

It is an arithmetic number, because the mean of its divisors is an integer number (101752560).

Almost surely, 2^767728721 is an apocalyptic number.

It is an amenable number.

767728721 is a deficient number, since it is larger than the sum of its proper divisors (46291759).

767728721 is a wasteful number, since it uses less digits than its factorization.

767728721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62863.

The product of its digits is 460992, while the sum is 47.

The square root of 767728721 is about 27707.9180199451. The cubic root of 767728721 is about 915.6635560199.

The spelling of 767728721 in words is "seven hundred sixty-seven million, seven hundred twenty-eight thousand, seven hundred twenty-one".