28761263820 has 36 divisors (see below), whose sum is σ = 87242500800. Its totient is φ = 7669670304.

The previous prime is 28761263809. The next prime is 28761263821. The reversal of 28761263820 is 2836216782.

28761263820 is a `hidden beast` number, since 2 + 8 + 7 + 6 + 1 + 2 + 638 + 2 + 0 = 666.

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 (45).

It is not an unprimeable number, because it can be changed into a prime (28761263821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 79892220 + ... + 79892579.

It is an arithmetic number, because the mean of its divisors is an integer number (2423402800).

Almost surely, 2^28761263820 is an apocalyptic number.

28761263820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28761263820 is an abundant number, since it is smaller than the sum of its proper divisors (58481236980).

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

28761263820 is a wasteful number, since it uses less digits than its factorization.

28761263820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159784814 (or 159784809 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 28761263820 in words is "twenty-eight billion, seven hundred sixty-one million, two hundred sixty-three thousand, eight hundred twenty".