21202049 has 4 divisors (see below), whose sum is σ = 23129520. Its totient is φ = 19274580.

The previous prime is 21202039. The next prime is 21202079. The reversal of 21202049 is 94020212.

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 21202049 - 2⁴ = 21202033 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21202049.

It is not an unprimeable number, because it can be changed into a prime (21202039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 963719 + ... + 963740.

It is an arithmetic number, because the mean of its divisors is an integer number (5782380).

Almost surely, 2^21202049 is an apocalyptic number.

It is an amenable number.

21202049 is a deficient number, since it is larger than the sum of its proper divisors (1927471).

21202049 is a wasteful number, since it uses less digits than its factorization.

21202049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1927470.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21202049 is about 4604.5682750938. The cubic root of 21202049 is about 276.7744169906.

The spelling of 21202049 in words is "twenty-one million, two hundred two thousand, forty-nine".