21223502 has 4 divisors (see below), whose sum is σ = 31835256. Its totient is φ = 10611750.

The previous prime is 21223487. The next prime is 21223507. The reversal of 21223502 is 20532212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5305874 + ... + 5305877.

It is an arithmetic number, because the mean of its divisors is an integer number (7958814).

Almost surely, 2^21223502 is an apocalyptic number.

21223502 is a deficient number, since it is larger than the sum of its proper divisors (10611754).

21223502 is a wasteful number, since it uses less digits than its factorization.

21223502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10611753.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21223502 is about 4606.8972204728. The cubic root of 21223502 is about 276.8677356450.

Adding to 21223502 its reverse (20532212), we get a palindrome (41755714).

The spelling of 21223502 in words is "twenty-one million, two hundred twenty-three thousand, five hundred two".