20446921 has 8 divisors (see below), whose sum is σ = 22536864. Its totient is φ = 18395520.

The previous prime is 20446897. The next prime is 20446957. The reversal of 20446921 is 12964402.

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

It is not a de Polignac number, because 20446921 - 2⁵ = 20446889 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20446921.

It is not an unprimeable number, because it can be changed into a prime (20446961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8515 + ... + 10648.

It is an arithmetic number, because the mean of its divisors is an integer number (2817108).

Almost surely, 2^20446921 is an apocalyptic number.

It is an amenable number.

20446921 is a deficient number, since it is larger than the sum of its proper divisors (2089943).

20446921 is a wasteful number, since it uses less digits than its factorization.

20446921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19271.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20446921 is about 4521.8271749371. The cubic root of 20446921 is about 273.4487692400.

The spelling of 20446921 in words is "twenty million, four hundred forty-six thousand, nine hundred twenty-one".