28120511440 has 40 divisors (see below), whose sum is σ = 74720217600. Its totient is φ = 9641318016.

The previous prime is 28120511437. The next prime is 28120511443. The reversal of 28120511440 is 4411502182.

It is an interprime number because it is at equal distance from previous prime (28120511437) and next prime (28120511443).

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 28120511399 and 28120511408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28120511443) 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 7 ways as a sum of consecutive naturals, for example, 25107040 + ... + 25108159.

It is an arithmetic number, because the mean of its divisors is an integer number (1868005440).

Almost surely, 2^28120511440 is an apocalyptic number.

28120511440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28120511440 is an abundant number, since it is smaller than the sum of its proper divisors (46599706160).

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

28120511440 is a wasteful number, since it uses less digits than its factorization.

28120511440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50215219 (or 50215213 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The spelling of 28120511440 in words is "twenty-eight billion, one hundred twenty million, five hundred eleven thousand, four hundred forty".