20439912 has 64 divisors (see below), whose sum is σ = 53544960. Its totient is φ = 6494400.

The previous prime is 20439911. The next prime is 20439917. The reversal of 20439912 is 21993402.

It is a self number, because there is not a number n which added to its sum of digits gives 20439912.

It is not an unprimeable number, because it can be changed into a prime (20439911) 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, 61587 + ... + 61917.

It is an arithmetic number, because the mean of its divisors is an integer number (836640).

Almost surely, 2^20439912 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20439912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26772480).

20439912 is an abundant number, since it is smaller than the sum of its proper divisors (33105048).

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

20439912 is a wasteful number, since it uses less digits than its factorization.

20439912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454 (or 450 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 20439912 is about 4521.0520899454. The cubic root of 20439912 is about 273.4175205015.

The spelling of 20439912 in words is "twenty million, four hundred thirty-nine thousand, nine hundred twelve".