20239890 has 32 divisors (see below), whose sum is σ = 52992576. Its totient is φ = 4906560.

The previous prime is 20239859. The next prime is 20239897. The reversal of 20239890 is 9893202.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (20239897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30337 + ... + 30996.

It is an arithmetic number, because the mean of its divisors is an integer number (1656018).

Almost surely, 2^20239890 is an apocalyptic number.

20239890 is an abundant number, since it is smaller than the sum of its proper divisors (32752686).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20239890 is a wasteful number, since it uses less digits than its factorization.

20239890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61354.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 20239890 is about 4498.8765264230. The cubic root of 20239890 is about 272.5227206597.

The spelling of 20239890 in words is "twenty million, two hundred thirty-nine thousand, eight hundred ninety".