20553660 has 72 divisors (see below), whose sum is σ = 63095760. Its totient is φ = 5415168.

The previous prime is 20553647. The next prime is 20553691. The reversal of 20553660 is 6635502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15379 + ... + 16661.

It is an arithmetic number, because the mean of its divisors is an integer number (876330).

Almost surely, 2^20553660 is an apocalyptic number.

20553660 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 20553660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31547880).

20553660 is an abundant number, since it is smaller than the sum of its proper divisors (42542100).

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

20553660 is a wasteful number, since it uses less digits than its factorization.

20553660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387 (or 1382 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The square root of 20553660 is about 4533.6144520680. The cubic root of 20553660 is about 273.9237715736.

The spelling of 20553660 in words is "twenty million, five hundred fifty-three thousand, six hundred sixty".