78506537 has 4 divisors (see below), whose sum is σ = 82638480. Its totient is φ = 74374596.

The previous prime is 78506507. The next prime is 78506543. The reversal of 78506537 is 73560587.

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: 73560587 = 179 ⋅410953.

It is a cyclic number.

It is not a de Polignac number, because 78506537 - 2¹⁰ = 78505513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78506494 and 78506503.

It is not an unprimeable number, because it can be changed into a prime (78506507) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2065943 + ... + 2065980.

It is an arithmetic number, because the mean of its divisors is an integer number (20659620).

Almost surely, 2^78506537 is an apocalyptic number.

It is an amenable number.

78506537 is a deficient number, since it is larger than the sum of its proper divisors (4131943).

78506537 is a wasteful number, since it uses less digits than its factorization.

78506537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4131942.

The product of its (nonzero) digits is 176400, while the sum is 41.

The square root of 78506537 is about 8860.3914699070. The cubic root of 78506537 is about 428.1887705600.

The spelling of 78506537 in words is "seventy-eight million, five hundred six thousand, five hundred thirty-seven".