20428408 has 64 divisors (see below), whose sum is σ = 51448320. Its totient is φ = 7344000.

The previous prime is 20428399. The next prime is 20428423. The reversal of 20428408 is 80482402.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6733 + ... + 9283.

It is an arithmetic number, because the mean of its divisors is an integer number (803880).

Almost surely, 2^20428408 is an apocalyptic number.

20428408 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20428408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25724160).

20428408 is an abundant number, since it is smaller than the sum of its proper divisors (31019912).

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

20428408 is a wasteful number, since it uses less digits than its factorization.

20428408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2588 (or 2584 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 28.

The square root of 20428408 is about 4519.7796406462. The cubic root of 20428408 is about 273.3662158867.

The spelling of 20428408 in words is "twenty million, four hundred twenty-eight thousand, four hundred eight".