20551620 has 24 divisors (see below), whose sum is σ = 57544704. Its totient is φ = 5480416.

The previous prime is 20551607. The next prime is 20551621. The reversal of 20551620 is 2615502.

It is not an unprimeable number, because it can be changed into a prime (20551621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171204 + ... + 171323.

It is an arithmetic number, because the mean of its divisors is an integer number (2397696).

Almost surely, 2^20551620 is an apocalyptic number.

20551620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20551620 is an abundant number, since it is smaller than the sum of its proper divisors (36993084).

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

20551620 is a wasteful number, since it uses less digits than its factorization.

20551620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342539 (or 342537 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 20551620 is about 4533.3894604369. The cubic root of 20551620 is about 273.9147087436.

The spelling of 20551620 in words is "twenty million, five hundred fifty-one thousand, six hundred twenty".