21620363 has 4 divisors (see below), whose sum is σ = 21834528. Its totient is φ = 21406200.

The previous prime is 21620359. The next prime is 21620369. The reversal of 21620363 is 36302612.

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 21620363 - 2² = 21620359 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21620369) 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 3 ways as a sum of consecutive naturals, for example, 106931 + ... + 107132.

It is an arithmetic number, because the mean of its divisors is an integer number (5458632).

Almost surely, 2^21620363 is an apocalyptic number.

21620363 is a deficient number, since it is larger than the sum of its proper divisors (214165).

21620363 is a wasteful number, since it uses less digits than its factorization.

21620363 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214164.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 21620363 is about 4649.7702093759. The cubic root of 21620363 is about 278.5828179683.

Adding to 21620363 its reverse (36302612), we get a palindrome (57922975).

The spelling of 21620363 in words is "twenty-one million, six hundred twenty thousand, three hundred sixty-three".