78399871 has 8 divisors (see below), whose sum is σ = 90028800. Its totient is φ = 67521240.

The previous prime is 78399859. The next prime is 78399877. The reversal of 78399871 is 17899387.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78399871 - 2¹³ = 78391679 is a prime.

It is a super-2 number, since 2×78399871² = 12293079545633282, 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 (78399877) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187351 + ... + 187768.

It is an arithmetic number, because the mean of its divisors is an integer number (11253600).

Almost surely, 2^78399871 is an apocalyptic number.

78399871 is a deficient number, since it is larger than the sum of its proper divisors (11628929).

78399871 is a wasteful number, since it uses less digits than its factorization.

78399871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375149.

The product of its digits is 762048, while the sum is 52.

The square root of 78399871 is about 8854.3701639360. The cubic root of 78399871 is about 427.9947574838.

The spelling of 78399871 in words is "seventy-eight million, three hundred ninety-nine thousand, eight hundred seventy-one".