78861851 has 4 divisors (see below), whose sum is σ = 79302600. Its totient is φ = 78421104.

The previous prime is 78861833. The next prime is 78861859. The reversal of 78861851 is 15816887.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78861851 - 2⁶ = 78861787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78861859) 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, 220106 + ... + 220463.

It is an arithmetic number, because the mean of its divisors is an integer number (19825650).

Almost surely, 2^78861851 is an apocalyptic number.

78861851 is a deficient number, since it is larger than the sum of its proper divisors (440749).

78861851 is a wasteful number, since it uses less digits than its factorization.

78861851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440748.

The product of its digits is 107520, while the sum is 44.

The square root of 78861851 is about 8880.4195283781. The cubic root of 78861851 is about 428.8337806000.

The spelling of 78861851 in words is "seventy-eight million, eight hundred sixty-one thousand, eight hundred fifty-one".