20399228 has 6 divisors (see below), whose sum is σ = 35698656. Its totient is φ = 10199612.

The previous prime is 20399227. The next prime is 20399231. The reversal of 20399228 is 82299302.

It is a super-2 number, since 2×20399228² = 832257005991968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20399221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2549900 + ... + 2549907.

It is an arithmetic number, because the mean of its divisors is an integer number (5949776).

Almost surely, 2^20399228 is an apocalyptic number.

It is an amenable number.

20399228 is a deficient number, since it is larger than the sum of its proper divisors (15299428).

20399228 is a wasteful number, since it uses less digits than its factorization.

20399228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5099811 (or 5099809 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 20399228 is about 4516.5504536095. The cubic root of 20399228 is about 273.2359948201.

The spelling of 20399228 in words is "twenty million, three hundred ninety-nine thousand, two hundred twenty-eight".