21001030 has 16 divisors (see below), whose sum is σ = 38150640. Its totient is φ = 8322912.

The previous prime is 21001021. The next prime is 21001033. The reversal of 21001030 is 3010012.

It is a super-2 number, since 2×21001030² = 882086522121800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001033) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8544 + ... + 10723.

It is an arithmetic number, because the mean of its divisors is an integer number (2384415).

Almost surely, 2^21001030 is an apocalyptic number.

21001030 is a deficient number, since it is larger than the sum of its proper divisors (17149610).

21001030 is a wasteful number, since it uses less digits than its factorization.

21001030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19383.

The product of its (nonzero) digits is 6, while the sum is 7.

The square root of 21001030 is about 4582.6880757913. The cubic root of 21001030 is about 275.8969281864.

Adding to 21001030 its reverse (3010012), we get a palindrome (24011042).

The spelling of 21001030 in words is "twenty-one million, one thousand, thirty".