78920819 has 8 divisors (see below), whose sum is σ = 80879040. Its totient is φ = 76983400.

The previous prime is 78920801. The next prime is 78920837. The reversal of 78920819 is 91802987.

It is an interprime number because it is at equal distance from previous prime (78920801) and next prime (78920837).

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 78920819 - 2²⁴ = 62143603 is a prime.

It is a super-2 number, since 2×78920819² = 12456991343261522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78920819.

It is not an unprimeable number, because it can be changed into a prime (78920879) 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, 2624 + ... + 12834.

It is an arithmetic number, because the mean of its divisors is an integer number (10109880).

Almost surely, 2^78920819 is an apocalyptic number.

78920819 is a deficient number, since it is larger than the sum of its proper divisors (1958221).

78920819 is a wasteful number, since it uses less digits than its factorization.

78920819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10401.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 78920819 is about 8883.7390213806. The cubic root of 78920819 is about 428.9406390699.

The spelling of 78920819 in words is "seventy-eight million, nine hundred twenty thousand, eight hundred nineteen".