78390886 has 24 divisors (see below), whose sum is σ = 141505920. Its totient is φ = 32436432.

The previous prime is 78390883. The next prime is 78390889. The reversal of 78390886 is 68809387.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (78390883) and next prime (78390889).

It is a super-2 number, since 2×78390886² = 12290262015729992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78390883) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10950 + ... + 16633.

It is an arithmetic number, because the mean of its divisors is an integer number (5896080).

Almost surely, 2^78390886 is an apocalyptic number.

78390886 is a deficient number, since it is larger than the sum of its proper divisors (63115034).

78390886 is a wasteful number, since it uses less digits than its factorization.

78390886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27628 (or 27621 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 49.

The square root of 78390886 is about 8853.8627728241. The cubic root of 78390886 is about 427.9784067774.

The spelling of 78390886 in words is "seventy-eight million, three hundred ninety thousand, eight hundred eighty-six".