820609585940 has 24 divisors (see below), whose sum is σ = 1724200273320. Its totient is φ = 328068569088.

The previous prime is 820609585907. The next prime is 820609585951. The reversal of 820609585940 is 49585906028.

It can be written as a sum of positive squares in 4 ways, for example, as 100019122564 + 720590463376 = 316258^2 + 848876^2 .

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, 10915685 + ... + 10990604.

It is an arithmetic number, because the mean of its divisors is an integer number (71841678055).

Almost surely, 2^820609585940 is an apocalyptic number.

It is an amenable number.

820609585940 is an abundant number, since it is smaller than the sum of its proper divisors (903590687380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820609585940 is a wasteful number, since it uses less digits than its factorization.

820609585940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21908171 (or 21908169 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 56.

The spelling of 820609585940 in words is "eight hundred twenty billion, six hundred nine million, five hundred eighty-five thousand, nine hundred forty".