28135949 has 4 divisors (see below), whose sum is σ = 28200480. Its totient is φ = 28071420.

The previous prime is 28135937. The next prime is 28135957. The reversal of 28135949 is 94953182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28135949 - 2¹² = 28131853 is a prime.

It is a super-2 number, since 2×28135949² = 1583263252261202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28135999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31607 + ... + 32484.

It is an arithmetic number, because the mean of its divisors is an integer number (7050120).

Almost surely, 2^28135949 is an apocalyptic number.

It is an amenable number.

28135949 is a deficient number, since it is larger than the sum of its proper divisors (64531).

28135949 is an equidigital number, since it uses as much as digits as its factorization.

28135949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64530.

The product of its digits is 77760, while the sum is 41.

The square root of 28135949 is about 5304.3330400721. Note that the first 3 decimals coincide. The cubic root of 28135949 is about 304.1495577875.

The spelling of 28135949 in words is "twenty-eight million, one hundred thirty-five thousand, nine hundred forty-nine".