78773220 has 36 divisors (see below), whose sum is σ = 238945980. Its totient is φ = 21006144.

The previous prime is 78773209. The next prime is 78773231. The reversal of 78773220 is 2237787.

It is an interprime number because it is at equal distance from previous prime (78773209) and next prime (78773231).

It can be written as a sum of positive squares in 2 ways, for example, as 49871844 + 28901376 = 7062^2 + 5376^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 218635 + ... + 218994.

Almost surely, 2^78773220 is an apocalyptic number.

It is an amenable number.

78773220 is an abundant number, since it is smaller than the sum of its proper divisors (160172760).

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

78773220 is a wasteful number, since it uses less digits than its factorization.

78773220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437644 (or 437639 counting only the distinct ones).

The product of its (nonzero) digits is 32928, while the sum is 36.

The square root of 78773220 is about 8875.4278770096. The cubic root of 78773220 is about 428.6730682742.

The spelling of 78773220 in words is "seventy-eight million, seven hundred seventy-three thousand, two hundred twenty".