821728119 has 12 divisors (see below), whose sum is σ = 1119453944. Its totient is φ = 536158704.

The previous prime is 821728069. The next prime is 821728121. The reversal of 821728119 is 911827128.

It is not a de Polignac number, because 821728119 - 2¹⁵ = 821695351 is a prime.

It is a super-2 number, since 2×821728119² = 1350474203110556322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821728619) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55372 + ... + 68625.

Almost surely, 2^821728119 is an apocalyptic number.

821728119 is a deficient number, since it is larger than the sum of its proper divisors (297725825).

821728119 is a wasteful number, since it uses less digits than its factorization.

821728119 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124094 (or 124047 counting only the distinct ones).

The product of its digits is 16128, while the sum is 39.

The square root of 821728119 is about 28665.8005121085. The cubic root of 821728119 is about 936.6472222478.

Subtracting 821728119 from its reverse (911827128), we obtain a palindrome (90099009).

The spelling of 821728119 in words is "eight hundred twenty-one million, seven hundred twenty-eight thousand, one hundred nineteen".