20551872 has 112 divisors (see below), whose sum is σ = 61155072. Its totient is φ = 6036480.

The previous prime is 20551871. The next prime is 20551877. The reversal of 20551872 is 27815502.

It is not an unprimeable number, because it can be changed into a prime (20551871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78013 + ... + 78275.

Almost surely, 2^20551872 is an apocalyptic number.

20551872 is a gapful number since it is divisible by the number (22) 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 20551872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30577536).

20551872 is an abundant number, since it is smaller than the sum of its proper divisors (40603200).

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

20551872 is a wasteful number, since it uses less digits than its factorization.

20551872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 20551872 is about 4533.4172541252. The cubic root of 20551872 is about 273.9158283021.

The spelling of 20551872 in words is "twenty million, five hundred fifty-one thousand, eight hundred seventy-two".