21026349 has 12 divisors (see below), whose sum is σ = 30594876. Its totient is φ = 13914432.

The previous prime is 21026333. The next prime is 21026351. The reversal of 21026349 is 94362012.

21026349 is a `hidden beast` number, since 21 + 0 + 2 + 634 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 10017225 + 11009124 = 3165^2 + 3318^2 .

It is not a de Polignac number, because 21026349 - 2⁴ = 21026333 is a prime.

It is a super-3 number, since 3×21026349³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21026359) 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 11 ways as a sum of consecutive naturals, for example, 7294 + ... + 9759.

It is an arithmetic number, because the mean of its divisors is an integer number (2549573).

Almost surely, 2^21026349 is an apocalyptic number.

It is an amenable number.

21026349 is a deficient number, since it is larger than the sum of its proper divisors (9568527).

21026349 is a wasteful number, since it uses less digits than its factorization.

21026349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17196 (or 17193 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 21026349 is about 4585.4497053179. The cubic root of 21026349 is about 276.0077581310.

The spelling of 21026349 in words is "twenty-one million, twenty-six thousand, three hundred forty-nine".