821965444 has 48 divisors (see below), whose sum is σ = 1561835520. Its totient is φ = 377336960.

The previous prime is 821965439. The next prime is 821965477. The reversal of 821965444 is 444569128.

It is a super-2 number, since 2×821965444² = 1351254382260234272, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 821965444.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 508782 + ... + 510394.

It is an arithmetic number, because the mean of its divisors is an integer number (32538240).

Almost surely, 2^821965444 is an apocalyptic number.

It is an amenable number.

821965444 is a deficient number, since it is larger than the sum of its proper divisors (739870076).

821965444 is a wasteful number, since it uses less digits than its factorization.

821965444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1860 (or 1858 counting only the distinct ones).

The product of its digits is 276480, while the sum is 43.

The square root of 821965444 is about 28669.9397278753. The cubic root of 821965444 is about 936.7373852430.

The spelling of 821965444 in words is "eight hundred twenty-one million, nine hundred sixty-five thousand, four hundred forty-four".