727856821 has 2 divisors, whose sum is σ = 727856822. Its totient is φ = 727856820.

The previous prime is 727856771. The next prime is 727856839. The reversal of 727856821 is 128658727.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 616975921 + 110880900 = 24839^2 + 10530^2 .

It is a cyclic number.

It is not a de Polignac number, because 727856821 - 2¹¹ = 727854773 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (727856861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 363928410 + 363928411.

It is an arithmetic number, because the mean of its divisors is an integer number (363928411).

Almost surely, 2^727856821 is an apocalyptic number.

It is an amenable number.

727856821 is a deficient number, since it is larger than the sum of its proper divisors (1).

727856821 is an equidigital number, since it uses as much as digits as its factorization.

727856821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 376320, while the sum is 46.

The square root of 727856821 is about 26978.8217125952. The cubic root of 727856821 is about 899.5293098442.

The spelling of 727856821 in words is "seven hundred twenty-seven million, eight hundred fifty-six thousand, eight hundred twenty-one".