20315280 has 80 divisors (see below), whose sum is σ = 64353024. Its totient is φ = 5299200.

The previous prime is 20315263. The next prime is 20315287. The reversal of 20315280 is 8251302.

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

It is not an unprimeable number, because it can be changed into a prime (20315287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10380 + ... + 12180.

Almost surely, 2^20315280 is an apocalyptic number.

20315280 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 20315280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32176512).

20315280 is an abundant number, since it is smaller than the sum of its proper divisors (44037744).

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

20315280 is a wasteful number, since it uses less digits than its factorization.

20315280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864 (or 1858 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 20315280 is about 4507.2474970873. The cubic root of 20315280 is about 272.8606676732.

Adding to 20315280 its reverse (8251302), we get a palindrome (28566582).

The spelling of 20315280 in words is "twenty million, three hundred fifteen thousand, two hundred eighty".