20211229 has 4 divisors (see below), whose sum is σ = 20220480. Its totient is φ = 20201980.

The previous prime is 20211221. The next prime is 20211241. The reversal of 20211229 is 92211202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20211229 - 2³ = 20211221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211221) 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, 684 + ... + 6394.

It is an arithmetic number, because the mean of its divisors is an integer number (5055120).

Almost surely, 2^20211229 is an apocalyptic number.

It is an amenable number.

20211229 is a deficient number, since it is larger than the sum of its proper divisors (9251).

20211229 is an equidigital number, since it uses as much as digits as its factorization.

20211229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9250.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 20211229 is about 4495.6900471452. The cubic root of 20211229 is about 272.3940232631.

The spelling of 20211229 in words is "twenty million, two hundred eleven thousand, two hundred twenty-nine".