78201920 has 28 divisors (see below), whose sum is σ = 186219084. Its totient is φ = 31280640.

The previous prime is 78201919. The next prime is 78201923. The reversal of 78201920 is 2910287.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 37650496 + 40551424 = 6136^2 + 6368^2 .

It is a super-2 number, since 2×78201920² = 12231080583372800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (78201923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121871 + ... + 122510.

Almost surely, 2^78201920 is an apocalyptic number.

It is an amenable number.

78201920 is an abundant number, since it is smaller than the sum of its proper divisors (108017164).

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

78201920 is a wasteful number, since it uses less digits than its factorization.

78201920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244398 (or 244388 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 78201920 is about 8843.1849466128. The cubic root of 78201920 is about 427.6342407554.

The spelling of 78201920 in words is "seventy-eight million, two hundred one thousand, nine hundred twenty".