28149940 has 48 divisors (see below), whose sum is σ = 72761472. Its totient is φ = 8908416.

The previous prime is 28149911. The next prime is 28149941. The reversal of 28149940 is 4994182.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 28149940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28149941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5914 + ... + 9553.

It is an arithmetic number, because the mean of its divisors is an integer number (1515864).

Almost surely, 2^28149940 is an apocalyptic number.

28149940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28149940 is an abundant number, since it is smaller than the sum of its proper divisors (44611532).

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

28149940 is a wasteful number, since it uses less digits than its factorization.

28149940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15496 (or 15494 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 28149940 is about 5305.6517036081. The cubic root of 28149940 is about 304.1999636616.

The spelling of 28149940 in words is "twenty-eight million, one hundred forty-nine thousand, nine hundred forty".