20400768 has 64 divisors (see below), whose sum is σ = 60220800. Its totient is φ = 6799104.

The previous prime is 20400719. The next prime is 20400803. The reversal of 20400768 is 86700402.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 505 + ... + 6407.

It is an arithmetic number, because the mean of its divisors is an integer number (940950).

Almost surely, 2^20400768 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 20400768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30110400).

20400768 is an abundant number, since it is smaller than the sum of its proper divisors (39820032).

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

20400768 is an equidigital number, since it uses as much as digits as its factorization.

20400768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5926 (or 5908 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 20400768 is about 4516.7209344833. The cubic root of 20400768 is about 273.2428704535.

The spelling of 20400768 in words is "twenty million, four hundred thousand, seven hundred sixty-eight".