21572049 has 16 divisors (see below), whose sum is σ = 30412800. Its totient is φ = 13563216.

The previous prime is 21572041. The next prime is 21572051. The reversal of 21572049 is 94027512.

It is not a de Polignac number, because 21572049 - 2³ = 21572041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21572041) 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, 14272 + ... + 15710.

It is an arithmetic number, because the mean of its divisors is an integer number (1900800).

Almost surely, 2^21572049 is an apocalyptic number.

It is an amenable number.

21572049 is a deficient number, since it is larger than the sum of its proper divisors (8840751).

21572049 is a wasteful number, since it uses less digits than its factorization.

21572049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1724.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 21572049 is about 4644.5719931981. The cubic root of 21572049 is about 278.3751512660.

The spelling of 21572049 in words is "twenty-one million, five hundred seventy-two thousand, forty-nine".