78408757 has 4 divisors (see below), whose sum is σ = 89610016. Its totient is φ = 67207500.

The previous prime is 78408749. The next prime is 78408761. The reversal of 78408757 is 75780487.

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: 75780487 = 131 ⋅578477.

It is a cyclic number.

It is not a de Polignac number, because 78408757 - 2³ = 78408749 is a prime.

It is a super-2 number, since 2×78408757² = 12295866348570098, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78408767) 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, 5600619 + ... + 5600632.

It is an arithmetic number, because the mean of its divisors is an integer number (22402504).

Almost surely, 2^78408757 is an apocalyptic number.

It is an amenable number.

78408757 is a deficient number, since it is larger than the sum of its proper divisors (11201259).

78408757 is a wasteful number, since it uses less digits than its factorization.

78408757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11201258.

The product of its (nonzero) digits is 439040, while the sum is 46.

The square root of 78408757 is about 8854.8719358328. The cubic root of 78408757 is about 428.0109268035.

The spelling of 78408757 in words is "seventy-eight million, four hundred eight thousand, seven hundred fifty-seven".