20551388 has 96 divisors (see below), whose sum is σ = 46663680. Its totient is φ = 7776000.

The previous prime is 20551387. The next prime is 20551393. The reversal of 20551388 is 88315502.

20551388 = T₂₂₇ + T₂₂₈ + ... + T₅₁₂.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20551387) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 336878 + ... + 336938.

It is an arithmetic number, because the mean of its divisors is an integer number (486080).

Almost surely, 2^20551388 is an apocalyptic number.

It is an amenable number.

20551388 is an abundant number, since it is smaller than the sum of its proper divisors (26112292).

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

20551388 is a wasteful number, since it uses less digits than its factorization.

20551388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 20551388 is about 4533.3638724462. The cubic root of 20551388 is about 273.9136780308.

It can be divided in two parts, 2055 and 1388, that added together give a palindrome (3443).

The spelling of 20551388 in words is "twenty million, five hundred fifty-one thousand, three hundred eighty-eight".