21004202 has 4 divisors (see below), whose sum is σ = 31506306. Its totient is φ = 10502100.

The previous prime is 21004189. The next prime is 21004211. The reversal of 21004202 is 20240012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18567481 + 2436721 = 4309^2 + 1561^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5251049 + ... + 5251052.

Almost surely, 2^21004202 is an apocalyptic number.

21004202 is a deficient number, since it is larger than the sum of its proper divisors (10502104).

21004202 is a wasteful number, since it uses less digits than its factorization.

21004202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10502103.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 21004202 is about 4583.0341478108. The cubic root of 21004202 is about 275.9108179972.

Adding to 21004202 its reverse (20240012), we get a palindrome (41244214).

The spelling of 21004202 in words is "twenty-one million, four thousand, two hundred two".