78861520 has 40 divisors (see below), whose sum is σ = 189273600. Its totient is φ = 30526080.

The previous prime is 78861499. The next prime is 78861557. The reversal of 78861520 is 2516887.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 78861520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13420 + ... + 18379.

It is an arithmetic number, because the mean of its divisors is an integer number (4731840).

Almost surely, 2^78861520 is an apocalyptic number.

It is an amenable number.

78861520 is an abundant number, since it is smaller than the sum of its proper divisors (110412080).

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

78861520 is a wasteful number, since it uses less digits than its factorization.

78861520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31843 (or 31837 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 78861520 is about 8880.4008918517. The cubic root of 78861520 is about 428.8331806302.

The spelling of 78861520 in words is "seventy-eight million, eight hundred sixty-one thousand, five hundred twenty".