28172949420 has 384 divisors, whose sum is σ = 102083788800. Its totient is φ = 5633971200.

The previous prime is 28172949419. The next prime is 28172949421. The reversal of 28172949420 is 2494927182.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28172949419) and next prime (28172949421).

It is a self number, because there is not a number n which added to its sum of digits gives 28172949420.

It is not an unprimeable number, because it can be changed into a prime (28172949421) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 32796951 + ... + 32797809.

It is an arithmetic number, because the mean of its divisors is an integer number (265843200).

Almost surely, 2^28172949420 is an apocalyptic number.

28172949420 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 28172949420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51041894400).

28172949420 is an abundant number, since it is smaller than the sum of its proper divisors (73910839380).

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

28172949420 is a wasteful number, since it uses less digits than its factorization.

28172949420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1149 (or 1147 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 48.

The spelling of 28172949420 in words is "twenty-eight billion, one hundred seventy-two million, nine hundred forty-nine thousand, four hundred twenty".