21203122 has 4 divisors (see below), whose sum is σ = 31804686. Its totient is φ = 10601560.

The previous prime is 21203113. The next prime is 21203123. The reversal of 21203122 is 22130212.

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

It can be written as a sum of positive squares in only one way, i.e., 10634121 + 10569001 = 3261^2 + 3251^2 .

It is not an unprimeable number, because it can be changed into a prime (21203123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5300779 + ... + 5300782.

Almost surely, 2^21203122 is an apocalyptic number.

21203122 is a deficient number, since it is larger than the sum of its proper divisors (10601564).

21203122 is a wasteful number, since it uses less digits than its factorization.

21203122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10601563.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21203122 is about 4604.6847883433. The cubic root of 21203122 is about 276.7790859409.

Adding to 21203122 its reverse (22130212), we get a palindrome (43333334).

The spelling of 21203122 in words is "twenty-one million, two hundred three thousand, one hundred twenty-two".