78389910 has 64 divisors (see below), whose sum is σ = 210124800. Its totient is φ = 20795616.

The previous prime is 78389891. The next prime is 78389921. The reversal of 78389910 is 1998387.

It is a super-2 number, since 2×78389910² = 12289955979616200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60651 + ... + 61929.

It is an arithmetic number, because the mean of its divisors is an integer number (3283200).

Almost surely, 2^78389910 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78389910, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105062400).

78389910 is an abundant number, since it is smaller than the sum of its proper divisors (131734890).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78389910 is a wasteful number, since it uses less digits than its factorization.

78389910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1522 (or 1516 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 78389910 is about 8853.8076554667. The cubic root of 78389910 is about 427.9766305987.

The spelling of 78389910 in words is "seventy-eight million, three hundred eighty-nine thousand, nine hundred ten".