78925349981 has 2 divisors, whose sum is σ = 78925349982. Its totient is φ = 78925349980.

The previous prime is 78925349969. The next prime is 78925350041. The reversal of 78925349981 is 18994352987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64584089956 + 14341260025 = 254134^2 + 119755^2 .

It is an emirp because it is prime and its reverse (18994352987) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78925349981 is a prime.

It is a super-2 number, since 2×78925349981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78925349681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39462674990 + 39462674991.

It is an arithmetic number, because the mean of its divisors is an integer number (39462674991).

Almost surely, 2^78925349981 is an apocalyptic number.

It is an amenable number.

78925349981 is a deficient number, since it is larger than the sum of its proper divisors (1).

78925349981 is an equidigital number, since it uses as much as digits as its factorization.

78925349981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39191040, while the sum is 65.

The spelling of 78925349981 in words is "seventy-eight billion, nine hundred twenty-five million, three hundred forty-nine thousand, nine hundred eighty-one".