21030355 has 8 divisors (see below), whose sum is σ = 25290000. Its totient is φ = 16788576.

The previous prime is 21030337. The next prime is 21030379. The reversal of 21030355 is 55303012.

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

It is a cyclic number.

It is not a de Polignac number, because 21030355 - 2⁷ = 21030227 is a prime.

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, 1720 + ... + 6709.

It is an arithmetic number, because the mean of its divisors is an integer number (3161250).

Almost surely, 2^21030355 is an apocalyptic number.

21030355 is a deficient number, since it is larger than the sum of its proper divisors (4259645).

21030355 is an equidigital number, since it uses as much as digits as its factorization.

21030355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8933.

The product of its (nonzero) digits is 450, while the sum is 19.

The square root of 21030355 is about 4585.8865009941. The cubic root of 21030355 is about 276.0252856131.

Adding to 21030355 its reverse (55303012), we get a palindrome (76333367).

The spelling of 21030355 in words is "twenty-one million, thirty thousand, three hundred fifty-five".