21125049 has 8 divisors (see below), whose sum is σ = 30727392. Its totient is φ = 12803040.

The previous prime is 21125029. The next prime is 21125057. The reversal of 21125049 is 94052112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21125049 - 2¹³ = 21116857 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21125029) 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 7 ways as a sum of consecutive naturals, for example, 320044 + ... + 320109.

It is an arithmetic number, because the mean of its divisors is an integer number (3840924).

Almost surely, 2^21125049 is an apocalyptic number.

It is an amenable number.

21125049 is a deficient number, since it is larger than the sum of its proper divisors (9602343).

21125049 is a wasteful number, since it uses less digits than its factorization.

21125049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640167.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 21125049 is about 4596.1994082067. The cubic root of 21125049 is about 276.4389544195.

The spelling of 21125049 in words is "twenty-one million, one hundred twenty-five thousand, forty-nine".