20147280 has 80 divisors (see below), whose sum is σ = 63043584. Its totient is φ = 5322240.

The previous prime is 20147273. The next prime is 20147297. The reversal of 20147280 is 8274102.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a self number, because there is not a number n which added to its sum of digits gives 20147280.

It is a congruent number.

It is an unprimeable number.

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, 30150 + ... + 30810.

Almost surely, 2^20147280 is an apocalyptic number.

20147280 is a gapful number since it is divisible by the number (20) 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 20147280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31521792).

20147280 is an abundant number, since it is smaller than the sum of its proper divisors (42896304).

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

20147280 is a wasteful number, since it uses less digits than its factorization.

20147280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804 (or 798 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 20147280 is about 4488.5721560425. The cubic root of 20147280 is about 272.1064318202.

The spelling of 20147280 in words is "twenty million, one hundred forty-seven thousand, two hundred eighty".