21016213 has 16 divisors (see below), whose sum is σ = 22550400. Its totient is φ = 19552960.

The previous prime is 21016201. The next prime is 21016217. The reversal of 21016213 is 31261012.

It is not a de Polignac number, because 21016213 - 2¹³ = 21008021 is a prime.

It is a super-2 number, since 2×21016213² = 883362417722738, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21016217) 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, 121395 + ... + 121567.

It is an arithmetic number, because the mean of its divisors is an integer number (1409400).

Almost surely, 2^21016213 is an apocalyptic number.

It is an amenable number.

21016213 is a deficient number, since it is larger than the sum of its proper divisors (1534187).

21016213 is a wasteful number, since it uses less digits than its factorization.

21016213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21016213 is about 4584.3443369799. The cubic root of 21016213 is about 275.9634000687.

Adding to 21016213 its reverse (31261012), we get a palindrome (52277225).

The spelling of 21016213 in words is "twenty-one million, sixteen thousand, two hundred thirteen".