20091229 has 16 divisors (see below), whose sum is σ = 22317120. Its totient is φ = 18000640.

The previous prime is 20091179. The next prime is 20091233. The reversal of 20091229 is 92219002.

It is a cyclic number.

It is not a de Polignac number, because 20091229 - 2⁷ = 20091101 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 (20091289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40674 + ... + 41164.

It is an arithmetic number, because the mean of its divisors is an integer number (1394820).

Almost surely, 2^20091229 is an apocalyptic number.

20091229 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20091229 is a deficient number, since it is larger than the sum of its proper divisors (2225891).

20091229 is a wasteful number, since it uses less digits than its factorization.

20091229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 20091229 is about 4482.3240623587. The cubic root of 20091229 is about 271.8538583816.

The spelling of 20091229 in words is "twenty million, ninety-one thousand, two hundred twenty-nine".