21008049 has 16 divisors (see below), whose sum is σ = 29038080. Its totient is φ = 13495680.

The previous prime is 21008041. The next prime is 21008081. The reversal of 21008049 is 94080012.

It is not a de Polignac number, because 21008049 - 2³ = 21008041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21008041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36637 + ... + 37205.

It is an arithmetic number, because the mean of its divisors is an integer number (1814880).

Almost surely, 2^21008049 is an apocalyptic number.

It is an amenable number.

21008049 is a deficient number, since it is larger than the sum of its proper divisors (8030031).

21008049 is a wasteful number, since it uses less digits than its factorization.

21008049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 21008049 is about 4583.4538287191. The cubic root of 21008049 is about 275.9276616764.

The spelling of 21008049 in words is "twenty-one million, eight thousand, forty-nine".