28144380 has 48 divisors (see below), whose sum is σ = 85970304. Its totient is φ = 6822720.

The previous prime is 28144331. The next prime is 28144393. The reversal of 28144380 is 8344182.

It is a super-2 number, since 2×28144380² = 1584212251168800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20662 + ... + 21981.

It is an arithmetic number, because the mean of its divisors is an integer number (1791048).

Almost surely, 2^28144380 is an apocalyptic number.

28144380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28144380 is an abundant number, since it is smaller than the sum of its proper divisors (57825924).

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

28144380 is a wasteful number, since it uses less digits than its factorization.

28144380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42666 (or 42664 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 28144380 is about 5305.1277081707. The cubic root of 28144380 is about 304.1799344518.

The spelling of 28144380 in words is "twenty-eight million, one hundred forty-four thousand, three hundred eighty".