278778620 has 48 divisors (see below), whose sum is σ = 602017920. Its totient is φ = 108386304.

The previous prime is 278778581. The next prime is 278778623. The reversal of 278778620 is 26877872.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278778623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146636 + ... + 148524.

It is an arithmetic number, because the mean of its divisors is an integer number (12542040).

Almost surely, 2^278778620 is an apocalyptic number.

278778620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

278778620 is an abundant number, since it is smaller than the sum of its proper divisors (323239300).

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

278778620 is a wasteful number, since it uses less digits than its factorization.

278778620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102 (or 2100 counting only the distinct ones).

The product of its (nonzero) digits is 526848, while the sum is 47.

The square root of 278778620 is about 16696.6649364476. The cubic root of 278778620 is about 653.2606338886.

The spelling of 278778620 in words is "two hundred seventy-eight million, seven hundred seventy-eight thousand, six hundred twenty".