821197442 has 64 divisors (see below), whose sum is σ = 1443294720. Its totient is φ = 347203584.

The previous prime is 821197439. The next prime is 821197463. The reversal of 821197442 is 244791128.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 821197396 and 821197405.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2623478 + ... + 2623790.

It is an arithmetic number, because the mean of its divisors is an integer number (22551480).

Almost surely, 2^821197442 is an apocalyptic number.

821197442 is a deficient number, since it is larger than the sum of its proper divisors (622097278).

821197442 is a wasteful number, since it uses less digits than its factorization.

821197442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507.

The product of its digits is 32256, while the sum is 38.

The square root of 821197442 is about 28656.5427433248. The cubic root of 821197442 is about 936.4455480096.

The spelling of 821197442 in words is "eight hundred twenty-one million, one hundred ninety-seven thousand, four hundred forty-two".