78400869 has 8 divisors (see below), whose sum is σ = 105460032. Its totient is φ = 51804480.

The previous prime is 78400867. The next prime is 78400871. The reversal of 78400869 is 96800487.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (78400867) and next prime (78400871).

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

It is not a de Polignac number, because 78400869 - 2¹ = 78400867 is a prime.

It is a super-2 number, since 2×78400869² = 12293392519910322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78400869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78400867) 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 7 ways as a sum of consecutive naturals, for example, 115297 + ... + 115974.

It is an arithmetic number, because the mean of its divisors is an integer number (13182504).

Almost surely, 2^78400869 is an apocalyptic number.

It is an amenable number.

78400869 is a deficient number, since it is larger than the sum of its proper divisors (27059163).

78400869 is a wasteful number, since it uses less digits than its factorization.

78400869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231387.

The product of its (nonzero) digits is 96768, while the sum is 42.

The square root of 78400869 is about 8854.4265201085. The cubic root of 78400869 is about 427.9965735452.

The spelling of 78400869 in words is "seventy-eight million, four hundred thousand, eight hundred sixty-nine".