21361293 has 8 divisors (see below), whose sum is σ = 31646400. Its totient is φ = 14240844.

The previous prime is 21361283. The next prime is 21361303. The reversal of 21361293 is 39216312.

It is an interprime number because it is at equal distance from previous prime (21361283) and next prime (21361303).

It is not a de Polignac number, because 21361293 - 2⁵ = 21361261 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 791159 = 21361293 / (2 + 1 + 3 + 6 + 1 + 2 + 9 + 3).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395553 + ... + 395606.

It is an arithmetic number, because the mean of its divisors is an integer number (3955800).

Almost surely, 2^21361293 is an apocalyptic number.

It is an amenable number.

21361293 is a deficient number, since it is larger than the sum of its proper divisors (10285107).

21361293 is an equidigital number, since it uses as much as digits as its factorization.

21361293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791168 (or 791162 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 21361293 is about 4621.8278851554. The cubic root of 21361293 is about 277.4656202843.

The spelling of 21361293 in words is "twenty-one million, three hundred sixty-one thousand, two hundred ninety-three".