78987806 has 4 divisors (see below), whose sum is σ = 118481712. Its totient is φ = 39493902.

The previous prime is 78987803. The next prime is 78987809. The reversal of 78987806 is 60878987.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60878987 = 13 ⋅4682999.

It is an interprime number because it is at equal distance from previous prime (78987803) and next prime (78987809).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78987803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19746950 + ... + 19746953.

It is an arithmetic number, because the mean of its divisors is an integer number (29620428).

Almost surely, 2^78987806 is an apocalyptic number.

78987806 is a deficient number, since it is larger than the sum of its proper divisors (39493906).

78987806 is a wasteful number, since it uses less digits than its factorization.

78987806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39493905.

The product of its (nonzero) digits is 1354752, while the sum is 53.

The square root of 78987806 is about 8887.5084247499. The cubic root of 78987806 is about 429.0619645590.

The spelling of 78987806 in words is "seventy-eight million, nine hundred eighty-seven thousand, eight hundred six".