78550913 has 4 divisors (see below), whose sum is σ = 89772480. Its totient is φ = 67329348.

The previous prime is 78550907. The next prime is 78550919. The reversal of 78550913 is 31905587.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31905587 = 7 ⋅4557941.

It is an interprime number because it is at equal distance from previous prime (78550907) and next prime (78550919).

It is a cyclic number.

It is not a de Polignac number, because 78550913 - 2⁸ = 78550657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78550919) 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, 5610773 + ... + 5610786.

It is an arithmetic number, because the mean of its divisors is an integer number (22443120).

Almost surely, 2^78550913 is an apocalyptic number.

It is an amenable number.

78550913 is a deficient number, since it is larger than the sum of its proper divisors (11221567).

78550913 is a wasteful number, since it uses less digits than its factorization.

78550913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11221566.

The product of its (nonzero) digits is 37800, while the sum is 38.

The square root of 78550913 is about 8862.8952944283. The cubic root of 78550913 is about 428.2694335916.

The spelling of 78550913 in words is "seventy-eight million, five hundred fifty thousand, nine hundred thirteen".