20556144 has 60 divisors (see below), whose sum is σ = 65750256. Its totient is φ = 5872896.

The previous prime is 20556121. The next prime is 20556149. The reversal of 20556144 is 44165502.

It is a super-2 number, since 2×20556144² = 845110112297472, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556149) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9189 + ... + 11204.

Almost surely, 2^20556144 is an apocalyptic number.

20556144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20556144 is an abundant number, since it is smaller than the sum of its proper divisors (45194112).

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

20556144 is a wasteful number, since it uses less digits than its factorization.

20556144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20414 (or 20405 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 20556144 is about 4533.8883973914. Note that the first 3 decimals coincide. The cubic root of 20556144 is about 273.9348060924.

The spelling of 20556144 in words is "twenty million, five hundred fifty-six thousand, one hundred forty-four".