20648881 has 4 divisors (see below), whose sum is σ = 22526064. Its totient is φ = 18771700.

The previous prime is 20648861. The next prime is 20648891. The reversal of 20648881 is 18884602.

20648881 is nontrivially palindromic in base 4 and base 15.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20648881 - 2¹¹ = 20646833 is a prime.

It is a super-2 number, since 2×20648881² = 852752573104322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20648881.

It is not an unprimeable number, because it can be changed into a prime (20648861) 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 3 ways as a sum of consecutive naturals, for example, 938575 + ... + 938596.

It is an arithmetic number, because the mean of its divisors is an integer number (5631516).

Almost surely, 2^20648881 is an apocalyptic number.

It is an amenable number.

20648881 is a deficient number, since it is larger than the sum of its proper divisors (1877183).

20648881 is a wasteful number, since it uses less digits than its factorization.

20648881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1877182.

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 20648881 is about 4544.1039820849. The cubic root of 20648881 is about 274.3461313746.

The spelling of 20648881 in words is "twenty million, six hundred forty-eight thousand, eight hundred eighty-one".