20402560 has 64 divisors (see below), whose sum is σ = 49572000. Its totient is φ = 8028160.

The previous prime is 20402537. The next prime is 20402563. The reversal of 20402560 is 6520402.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45216 + ... + 45664.

Almost surely, 2^20402560 is an apocalyptic number.

20402560 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 20402560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24786000).

20402560 is an abundant number, since it is smaller than the sum of its proper divisors (29169440).

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

20402560 is an equidigital number, since it uses as much as digits as its factorization.

With its predecessor (20402559) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (539).

20402560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539 (or 527 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20402560 is about 4516.9193041275. The cubic root of 20402560 is about 273.2508707551.

Adding to 20402560 its reverse (6520402), we get a palindrome (26922962).

The spelling of 20402560 in words is "twenty million, four hundred two thousand, five hundred sixty".