78386920 has 16 divisors (see below), whose sum is σ = 176370660. Its totient is φ = 31354752.

The previous prime is 78386909. The next prime is 78386933. The reversal of 78386920 is 2968387.

It can be written as a sum of positive squares in 2 ways, for example, as 78110244 + 276676 = 8838^2 + 526^2 .

It is a super-2 number, since 2×78386920² = 12289018454172800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 979797 + ... + 979876.

Almost surely, 2^78386920 is an apocalyptic number.

It is an amenable number.

78386920 is an abundant number, since it is smaller than the sum of its proper divisors (97983740).

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

78386920 is a wasteful number, since it uses less digits than its factorization.

78386920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1959684 (or 1959680 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 78386920 is about 8853.6387999511. The cubic root of 78386920 is about 427.9711891399.

The spelling of 78386920 in words is "seventy-eight million, three hundred eighty-six thousand, nine hundred twenty".