21030307 has 16 divisors (see below), whose sum is σ = 22752000. Its totient is φ = 19393920.

The previous prime is 21030301. The next prime is 21030313. The reversal of 21030307 is 70303012.

It is an interprime number because it is at equal distance from previous prime (21030301) and next prime (21030313).

It is a cyclic number.

It is not a de Polignac number, because 21030307 - 2¹⁵ = 20997539 is a prime.

It is a super-3 number, since 3×21030307³ (a number of 23 digits) contains 333 as substring.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133873 + ... + 134029.

It is an arithmetic number, because the mean of its divisors is an integer number (1422000).

Almost surely, 2^21030307 is an apocalyptic number.

21030307 is a deficient number, since it is larger than the sum of its proper divisors (1721693).

21030307 is a wasteful number, since it uses less digits than its factorization.

21030307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366.

The product of its (nonzero) digits is 126, while the sum is 16.

The square root of 21030307 is about 4585.8812675428. The cubic root of 21030307 is about 276.0250756115.

Adding to 21030307 its reverse (70303012), we get a palindrome (91333319).

The spelling of 21030307 in words is "twenty-one million, thirty thousand, three hundred seven".