78279431 has 4 divisors (see below), whose sum is σ = 78607200. Its totient is φ = 77951664.

The previous prime is 78279427. The next prime is 78279469. The reversal of 78279431 is 13497287.

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 78279431 - 2² = 78279427 is a prime.

It is a super-3 number, since 3×78279431³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78279401) 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, 163526 + ... + 164003.

It is an arithmetic number, because the mean of its divisors is an integer number (19651800).

Almost surely, 2^78279431 is an apocalyptic number.

78279431 is a deficient number, since it is larger than the sum of its proper divisors (327769).

78279431 is a wasteful number, since it uses less digits than its factorization.

78279431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327768.

The product of its digits is 84672, while the sum is 41.

The square root of 78279431 is about 8847.5663885613. The cubic root of 78279431 is about 427.7754794552.

The spelling of 78279431 in words is "seventy-eight million, two hundred seventy-nine thousand, four hundred thirty-one".