20551331 has 8 divisors (see below), whose sum is σ = 21718800. Its totient is φ = 19392480.

The previous prime is 20551303. The next prime is 20551367. The reversal of 20551331 is 13315502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20551331 - 2¹⁸ = 20289187 is a prime.

It is a super-2 number, since 2×20551331² = 844714411743122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20551231) 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, 3101 + ... + 7121.

It is an arithmetic number, because the mean of its divisors is an integer number (2714850).

Almost surely, 2^20551331 is an apocalyptic number.

20551331 is a deficient number, since it is larger than the sum of its proper divisors (1167469).

20551331 is a wasteful number, since it uses less digits than its factorization.

20551331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4309.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 20551331 is about 4533.3575857194. The cubic root of 20551331 is about 273.9134247942.

Adding to 20551331 its reverse (13315502), we get a palindrome (33866833).

The spelling of 20551331 in words is "twenty million, five hundred fifty-one thousand, three hundred thirty-one".