28766440 has 32 divisors (see below), whose sum is σ = 65114280. Its totient is φ = 11437312.

The previous prime is 28766429. The next prime is 28766443. The reversal of 28766440 is 4466782.

It can be written as a sum of positive squares in 4 ways, for example, as 27060804 + 1705636 = 5202^2 + 1306^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28766440.

It is not an unprimeable number, because it can be changed into a prime (28766443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4842 + ... + 8998.

Almost surely, 2^28766440 is an apocalyptic number.

28766440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28766440 is an abundant number, since it is smaller than the sum of its proper divisors (36347840).

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

28766440 is a wasteful number, since it uses less digits than its factorization.

28766440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4341 (or 4337 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 37.

The square root of 28766440 is about 5363.4354661914. The cubic root of 28766440 is about 306.4046649004.

It can be divided in two parts, 2876 and 6440, that added together give a triangular number (9316 = T₁₃₆).

The spelling of 28766440 in words is "twenty-eight million, seven hundred sixty-six thousand, four hundred forty".