21016331 has 16 divisors (see below), whose sum is σ = 24660480. Its totient is φ = 17539200.

The previous prime is 21016309. The next prime is 21016381. The reversal of 21016331 is 13361012.

It is a de Polignac number, because none of the positive numbers 2^k-21016331 is a prime.

It is a super-2 number, since 2×21016331² = 883372337403122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21016381) 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, 62195 + ... + 62531.

It is an arithmetic number, because the mean of its divisors is an integer number (1541280).

Almost surely, 2^21016331 is an apocalyptic number.

21016331 is a deficient number, since it is larger than the sum of its proper divisors (3644149).

21016331 is a wasteful number, since it uses less digits than its factorization.

21016331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 21016331 is about 4584.3572068503. The cubic root of 21016331 is about 275.9639165528.

Adding to 21016331 its reverse (13361012), we get a palindrome (34377343).

The spelling of 21016331 in words is "twenty-one million, sixteen thousand, three hundred thirty-one".