21030361 has 4 divisors (see below), whose sum is σ = 22942224. Its totient is φ = 19118500.

The previous prime is 21030337. The next prime is 21030379. The reversal of 21030361 is 16303012.

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 21030361 - 2⁵ = 21030329 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21030301) 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, 955915 + ... + 955936.

It is an arithmetic number, because the mean of its divisors is an integer number (5735556).

Almost surely, 2^21030361 is an apocalyptic number.

It is an amenable number.

21030361 is a deficient number, since it is larger than the sum of its proper divisors (1911863).

21030361 is a wasteful number, since it uses less digits than its factorization.

21030361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1911862.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 21030361 is about 4585.8871551751. The cubic root of 21030361 is about 276.0253118633.

Adding to 21030361 its reverse (16303012), we get a palindrome (37333373).

The spelling of 21030361 in words is "twenty-one million, thirty thousand, three hundred sixty-one".