820739947688 has 16 divisors (see below), whose sum is σ = 1619881476000. Its totient is φ = 388771554096.

The previous prime is 820739947663. The next prime is 820739947691. The reversal of 820739947688 is 886749937028.

It is a super-2 number, since 2×820739947688² (a number of 25 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (71) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2699802308 + ... + 2699802611.

It is an arithmetic number, because the mean of its divisors is an integer number (101242592250).

Almost surely, 2^820739947688 is an apocalyptic number.

It is an amenable number.

820739947688 is a deficient number, since it is larger than the sum of its proper divisors (799141528312).

820739947688 is a wasteful number, since it uses less digits than its factorization.

820739947688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5399604944 (or 5399604940 counting only the distinct ones).

The product of its (nonzero) digits is 292626432, while the sum is 71.

The spelling of 820739947688 in words is "eight hundred twenty billion, seven hundred thirty-nine million, nine hundred forty-seven thousand, six hundred eighty-eight".