22001231 has 4 divisors (see below), whose sum is σ = 25144272. Its totient is φ = 18858192.

The previous prime is 22001209. The next prime is 22001237. The reversal of 22001231 is 13210022.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22001231 is a prime.

It is a super-2 number, since 2×22001231² = 968108331030722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22001237) 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, 1571510 + ... + 1571523.

It is an arithmetic number, because the mean of its divisors is an integer number (6286068).

Almost surely, 2^22001231 is an apocalyptic number.

22001231 is a deficient number, since it is larger than the sum of its proper divisors (3143041).

22001231 is an equidigital number, since it uses as much as digits as its factorization.

22001231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3143040.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 22001231 is about 4690.5469830287. The cubic root of 22001231 is about 280.2091591960.

Adding to 22001231 its reverse (13210022), we get a palindrome (35211253).

The spelling of 22001231 in words is "twenty-two million, one thousand, two hundred thirty-one".