28121701500 has 240 divisors, whose sum is σ = 93259822656. Its totient is φ = 7375536000.

The previous prime is 28121701493. The next prime is 28121701501. The reversal of 28121701500 is 510712182.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28121701501) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2464809 + ... + 2476191.

Almost surely, 2^28121701500 is an apocalyptic number.

28121701500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28121701500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46629911328).

28121701500 is an abundant number, since it is smaller than the sum of its proper divisors (65138121156).

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

28121701500 is a wasteful number, since it uses less digits than its factorization.

28121701500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11475 (or 11454 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The spelling of 28121701500 in words is "twenty-eight billion, one hundred twenty-one million, seven hundred one thousand, five hundred".