21253179 has 16 divisors (see below), whose sum is σ = 30119040. Its totient is φ = 13284480.

The previous prime is 21253121. The next prime is 21253181. The reversal of 21253179 is 97135212.

It is not a de Polignac number, because 21253179 - 2¹⁹ = 20728891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21253109) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 16252 + ... + 17510.

It is an arithmetic number, because the mean of its divisors is an integer number (1882440).

Almost surely, 2^21253179 is an apocalyptic number.

21253179 is a deficient number, since it is larger than the sum of its proper divisors (8865861).

21253179 is a wasteful number, since it uses less digits than its factorization.

21253179 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1610.

The product of its digits is 3780, while the sum is 30.

The square root of 21253179 is about 4610.1170267142. The cubic root of 21253179 is about 276.9967243636.

The spelling of 21253179 in words is "twenty-one million, two hundred fifty-three thousand, one hundred seventy-nine".