28912213 has 4 divisors (see below), whose sum is σ = 31540608. Its totient is φ = 26283820.

The previous prime is 28912193. The next prime is 28912249. The reversal of 28912213 is 31221982.

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 28912213 - 2¹³ = 28904021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28912283) 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, 1314181 + ... + 1314202.

It is an arithmetic number, because the mean of its divisors is an integer number (7885152).

Almost surely, 2^28912213 is an apocalyptic number.

It is an amenable number.

28912213 is a deficient number, since it is larger than the sum of its proper divisors (2628395).

28912213 is a wasteful number, since it uses less digits than its factorization.

28912213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2628394.

The product of its digits is 1728, while the sum is 28.

The square root of 28912213 is about 5377.0078110414. The cubic root of 28912213 is about 306.9213583329.

The spelling of 28912213 in words is "twenty-eight million, nine hundred twelve thousand, two hundred thirteen".