78981517 has 4 divisors (see below), whose sum is σ = 82415520. Its totient is φ = 75547516.

The previous prime is 78981503. The next prime is 78981523. The reversal of 78981517 is 71518987.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78981517 - 2¹¹ = 78979469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78981527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1716967 + ... + 1717012.

It is an arithmetic number, because the mean of its divisors is an integer number (20603880).

Almost surely, 2^78981517 is an apocalyptic number.

It is an amenable number.

78981517 is a deficient number, since it is larger than the sum of its proper divisors (3434003).

78981517 is a wasteful number, since it uses less digits than its factorization.

78981517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3434002.

The product of its digits is 141120, while the sum is 46.

The square root of 78981517 is about 8887.1546065093. The cubic root of 78981517 is about 429.0505769687.

The spelling of 78981517 in words is "seventy-eight million, nine hundred eighty-one thousand, five hundred seventeen".