21698313 has 16 divisors (see below), whose sum is σ = 35607936. Its totient is φ = 11445120.

The previous prime is 21698311. The next prime is 21698321. The reversal of 21698313 is 31389612.

It is not a de Polignac number, because 21698313 - 2¹ = 21698311 is a prime.

It is a super-3 number, since 3×21698313³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21698311) 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, 39468 + ... + 40013.

It is an arithmetic number, because the mean of its divisors is an integer number (2225496).

Almost surely, 2^21698313 is an apocalyptic number.

It is an amenable number.

21698313 is a deficient number, since it is larger than the sum of its proper divisors (13909623).

21698313 is a wasteful number, since it uses less digits than its factorization.

21698313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79504.

The product of its digits is 7776, while the sum is 33.

The square root of 21698313 is about 4658.1448023865. The cubic root of 21698313 is about 278.9172169961.

The spelling of 21698313 in words is "twenty-one million, six hundred ninety-eight thousand, three hundred thirteen".