7861804739881 has 3 divisors (see below), whose sum is σ = 7861807543773. Its totient is φ = 7861801935990.

The previous prime is 7861804739869. The next prime is 7861804739923. The reversal of 7861804739881 is 1889374081687.

The square root of 7861804739881 is 2803891.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 7861804739881 - 2⁷ = 7861804739753 is a prime.

It is a super-2 number, since 2×7861804739881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7861804739881.

It is not an unprimeable number, because it can be changed into a prime (7861804739081) 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 2 ways as a sum of consecutive naturals, for example, 1401946 + ... + 4205836.

It is an arithmetic number, because the mean of its divisors is an integer number (2620602514591).

Almost surely, 2^{7861804739881} is an apocalyptic number.

7861804739881 is the 2803891-st square number.

7861804739881 is the 1401946-th centered octagonal number.

It is an amenable number.

7861804739881 is a deficient number, since it is larger than the sum of its proper divisors (2803892).

7861804739881 is an frugal number, since it uses more digits than its factorization.

7861804739881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5607782 (or 2803891 counting only the distinct ones).

The product of its (nonzero) digits is 130056192, while the sum is 70.

The spelling of 7861804739881 in words is "seven trillion, eight hundred sixty-one billion, eight hundred four million, seven hundred thirty-nine thousand, eight hundred eighty-one".