28999620 has 216 divisors, whose sum is σ = 104157144. Its totient is φ = 6718464.

The previous prime is 28999613. The next prime is 28999651. The reversal of 28999620 is 2699982.

It can be written as a sum of positive squares in 4 ways, for example, as 2125764 + 26873856 = 1458^2 + 5184^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1705852 + ... + 1705868.

It is an arithmetic number, because the mean of its divisors is an integer number (482209).

Almost surely, 2^28999620 is an apocalyptic number.

28999620 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 28999620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52078572).

28999620 is an abundant number, since it is smaller than the sum of its proper divisors (75157524).

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

28999620 is a wasteful number, since it uses less digits than its factorization.

28999620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63 (or 40 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 28999620 is about 5385.1295249047. The cubic root of 28999620 is about 307.2303406312.

The spelling of 28999620 in words is "twenty-eight million, nine hundred ninety-nine thousand, six hundred twenty".