7939397124821 has 8 divisors (see below), whose sum is σ = 8213374564920. Its totient is φ = 7665433359808.

The previous prime is 7939397124793. The next prime is 7939397124871. The reversal of 7939397124821 is 1284217939397.

It can be written as a sum of positive squares in 4 ways, for example, as 5485380883921 + 2454016240900 = 2342089^2 + 1566530^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7939397124821 - 2¹⁰ = 7939397123797 is a prime.

It is a super-2 number, since 2×7939397124821² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7939397124871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2230586 + ... + 4566651.

It is an arithmetic number, because the mean of its divisors is an integer number (1026671820615).

Almost surely, 2^{7939397124821} is an apocalyptic number.

It is an amenable number.

7939397124821 is a deficient number, since it is larger than the sum of its proper divisors (273977440099).

7939397124821 is a wasteful number, since it uses less digits than its factorization.

7939397124821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6837543.

The product of its digits is 41150592, while the sum is 65.

The spelling of 7939397124821 in words is "seven trillion, nine hundred thirty-nine billion, three hundred ninety-seven million, one hundred twenty-four thousand, eight hundred twenty-one".