21602231 has 4 divisors (see below), whose sum is σ = 24688272. Its totient is φ = 18516192.

The previous prime is 21602197. The next prime is 21602237. The reversal of 21602231 is 13220612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21602231 - 2¹⁴ = 21585847 is a prime.

It is a super-2 number, since 2×21602231² = 933312768354722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21602237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1543010 + ... + 1543023.

It is an arithmetic number, because the mean of its divisors is an integer number (6172068).

Almost surely, 2^21602231 is an apocalyptic number.

21602231 is a deficient number, since it is larger than the sum of its proper divisors (3086041).

21602231 is an equidigital number, since it uses as much as digits as its factorization.

21602231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3086040.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21602231 is about 4647.8200266361. The cubic root of 21602231 is about 278.5049180058.

Adding to 21602231 its reverse (13220612), we get a palindrome (34822843).

It can be divided in two parts, 2160 and 2231, that multiplied together give a triangular number (4818960 = T₃₁₀₄).

The spelling of 21602231 in words is "twenty-one million, six hundred two thousand, two hundred thirty-one".