28131436 has 24 divisors (see below), whose sum is σ = 50400000. Its totient is φ = 13734864.

The previous prime is 28131409. The next prime is 28131449. The reversal of 28131436 is 63413182.

28131436 = T₁₅₉ + T₁₆₀ + ... + T₅₅₆.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46665 + ... + 47263.

It is an arithmetic number, because the mean of its divisors is an integer number (2100000).

Almost surely, 2^28131436 is an apocalyptic number.

It is an amenable number.

28131436 is a deficient number, since it is larger than the sum of its proper divisors (22268564).

28131436 is a wasteful number, since it uses less digits than its factorization.

28131436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 861 (or 859 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 28131436 is about 5303.9076160883. The cubic root of 28131436 is about 304.1332950773.

The spelling of 28131436 in words is "twenty-eight million, one hundred thirty-one thousand, four hundred thirty-six".