28139956 has 12 divisors (see below), whose sum is σ = 53033092. Its totient is φ = 12987648.

The previous prime is 28139941. The next prime is 28139957. The reversal of 28139956 is 65993182.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16810000 + 11329956 = 4100^2 + 3366^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28139957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 270525 + ... + 270628.

Almost surely, 2^28139956 is an apocalyptic number.

28139956 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

28139956 is a deficient number, since it is larger than the sum of its proper divisors (24893136).

28139956 is a wasteful number, since it uses less digits than its factorization.

28139956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541170 (or 541168 counting only the distinct ones).

The product of its digits is 116640, while the sum is 43.

The square root of 28139956 is about 5304.7107366943. The cubic root of 28139956 is about 304.1639956564.

It can be divided in two parts, 2813 and 9956, that added together give a square (12769 = 113²).

The spelling of 28139956 in words is "twenty-eight million, one hundred thirty-nine thousand, nine hundred fifty-six".