28778040 has 48 divisors (see below), whose sum is σ = 93529800. Its totient is φ = 7674048.

The previous prime is 28778039. The next prime is 28778047. The reversal of 28778040 is 4087782.

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

It is a junction number, because it is equal to n+sod(n) for n = 28777986 and 28778004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28778047) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39610 + ... + 40329.

Almost surely, 2^28778040 is an apocalyptic number.

28778040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28778040 is an abundant number, since it is smaller than the sum of its proper divisors (64751760).

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

28778040 is a wasteful number, since it uses less digits than its factorization.

28778040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79956 (or 79949 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 28778040 is about 5364.5167536321. The cubic root of 28778040 is about 306.4458450218.

The spelling of 28778040 in words is "twenty-eight million, seven hundred seventy-eight thousand, forty".