22215251 has 4 divisors (see below), whose sum is σ = 22931904. Its totient is φ = 21498600.

The previous prime is 22215241. The next prime is 22215269. The reversal of 22215251 is 15251222.

It is a happy number.

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 22215251 - 2⁶ = 22215187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22215241) 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, 358280 + ... + 358341.

It is an arithmetic number, because the mean of its divisors is an integer number (5732976).

Almost surely, 2^22215251 is an apocalyptic number.

22215251 is a deficient number, since it is larger than the sum of its proper divisors (716653).

22215251 is an equidigital number, since it uses as much as digits as its factorization.

22215251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716652.

The product of its digits is 400, while the sum is 20.

The square root of 22215251 is about 4713.3057401361. The cubic root of 22215251 is about 281.1148199098.

Adding to 22215251 its reverse (15251222), we get a palindrome (37466473).

The spelling of 22215251 in words is "twenty-two million, two hundred fifteen thousand, two hundred fifty-one".