20551540 has 24 divisors (see below), whose sum is σ = 45430560. Its totient is φ = 7787808.

The previous prime is 20551523. The next prime is 20551561. The reversal of 20551540 is 4515502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26662 + ... + 27421.

It is an arithmetic number, because the mean of its divisors is an integer number (1892940).

Almost surely, 2^20551540 is an apocalyptic number.

20551540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20551540 is an abundant number, since it is smaller than the sum of its proper divisors (24879020).

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

20551540 is a wasteful number, since it uses less digits than its factorization.

20551540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54111 (or 54109 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 20551540 is about 4533.3806370081. The cubic root of 20551540 is about 273.9143533263.

The spelling of 20551540 in words is "twenty million, five hundred fifty-one thousand, five hundred forty".