821994395 has 8 divisors (see below), whose sum is σ = 986934480. Its totient is φ = 657234720.

The previous prime is 821994379. The next prime is 821994427. The reversal of 821994395 is 593499128.

It is a happy number.

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

It is not a de Polignac number, because 821994395 - 2⁴ = 821994379 is a prime.

It is a super-2 number, since 2×821994395² = 1351349570822832050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34865 + ... + 53474.

It is an arithmetic number, because the mean of its divisors is an integer number (123366810).

Almost surely, 2^821994395 is an apocalyptic number.

821994395 is a deficient number, since it is larger than the sum of its proper divisors (164940085).

821994395 is a wasteful number, since it uses less digits than its factorization.

821994395 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90205.

The product of its digits is 699840, while the sum is 50.

The square root of 821994395 is about 28670.4446250839. Note that the first 3 decimals coincide. The cubic root of 821994395 is about 936.7483829339.

The spelling of 821994395 in words is "eight hundred twenty-one million, nine hundred ninety-four thousand, three hundred ninety-five".