21002245 has 8 divisors (see below), whose sum is σ = 27493920. Its totient is φ = 15274320.

The previous prime is 21002231. The next prime is 21002251. The reversal of 21002245 is 54220012.

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

It is not a de Polignac number, because 21002245 - 2⁵ = 21002213 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190875 + ... + 190984.

It is an arithmetic number, because the mean of its divisors is an integer number (3436740).

Almost surely, 2^21002245 is an apocalyptic number.

It is an amenable number.

21002245 is a deficient number, since it is larger than the sum of its proper divisors (6491675).

21002245 is a wasteful number, since it uses less digits than its factorization.

21002245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381875.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 21002245 is about 4582.8206379914. The cubic root of 21002245 is about 275.9022486922.

Adding to 21002245 its reverse (54220012), we get a palindrome (75222257).

The spelling of 21002245 in words is "twenty-one million, two thousand, two hundred forty-five".