20420736 has 128 divisors (see below), whose sum is σ = 63452160. Its totient is φ = 5698560.

The previous prime is 20420681. The next prime is 20420759. The reversal of 20420736 is 63702402.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 190795 + ... + 190901.

It is an arithmetic number, because the mean of its divisors is an integer number (495720).

Almost surely, 2^20420736 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 20420736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31726080).

20420736 is an abundant number, since it is smaller than the sum of its proper divisors (43031424).

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

20420736 is a wasteful number, since it uses less digits than its factorization.

20420736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 190 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 20420736 is about 4518.9308470035. The cubic root of 20420736 is about 273.3319902109.

The spelling of 20420736 in words is "twenty million, four hundred twenty thousand, seven hundred thirty-six".