78811405981 has 24 divisors (see below), whose sum is σ = 101763514944. Its totient is φ = 59293799040.

The previous prime is 78811405961. The next prime is 78811406017. The reversal of 78811405981 is 18950411887.

It is not a de Polignac number, because 78811405981 - 2⁵ = 78811405949 is a prime.

It is a super-2 number, since 2×78811405981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78811405961) 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 23 ways as a sum of consecutive naturals, for example, 543760 + ... + 673273.

It is an arithmetic number, because the mean of its divisors is an integer number (4240146456).

Almost surely, 2^78811405981 is an apocalyptic number.

It is an amenable number.

78811405981 is a deficient number, since it is larger than the sum of its proper divisors (22952108963).

78811405981 is a wasteful number, since it uses less digits than its factorization.

78811405981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217109 (or 1217080 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 52.

The spelling of 78811405981 in words is "seventy-eight billion, eight hundred eleven million, four hundred five thousand, nine hundred eighty-one".