820872821624 has 32 divisors (see below), whose sum is σ = 1547350179840. Its totient is φ = 408246540000.

The previous prime is 820872821599. The next prime is 820872821647. The reversal of 820872821624 is 426128278028.

It is a happy number.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 20123249 + ... + 20163999.

It is an arithmetic number, because the mean of its divisors is an integer number (48354693120).

Almost surely, 2^820872821624 is an apocalyptic number.

It is an amenable number.

820872821624 is a deficient number, since it is larger than the sum of its proper divisors (726477358216).

820872821624 is a wasteful number, since it uses less digits than its factorization.

820872821624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54131 (or 54127 counting only the distinct ones).

The product of its (nonzero) digits is 1376256, while the sum is 50.

The spelling of 820872821624 in words is "eight hundred twenty billion, eight hundred seventy-two million, eight hundred twenty-one thousand, six hundred twenty-four".