78987451 has 4 divisors (see below), whose sum is σ = 82421712. Its totient is φ = 75553192.

The previous prime is 78987449. The next prime is 78987481. The reversal of 78987451 is 15478987.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15478987 = 37 ⋅418351.

It is a cyclic number.

It is not a de Polignac number, because 78987451 - 2¹ = 78987449 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78987395 and 78987404.

It is not an unprimeable number, because it can be changed into a prime (78987481) 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, 1717096 + ... + 1717141.

It is an arithmetic number, because the mean of its divisors is an integer number (20605428).

Almost surely, 2^78987451 is an apocalyptic number.

78987451 is a deficient number, since it is larger than the sum of its proper divisors (3434261).

78987451 is a wasteful number, since it uses less digits than its factorization.

78987451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3434260.

The product of its digits is 564480, while the sum is 49.

The square root of 78987451 is about 8887.4884528758. The cubic root of 78987451 is about 429.0613217710.

The spelling of 78987451 in words is "seventy-eight million, nine hundred eighty-seven thousand, four hundred fifty-one".