20145554221 has 16 divisors (see below), whose sum is σ = 22257305280. Its totient is φ = 18115447680.

The previous prime is 20145554201. The next prime is 20145554239. The reversal of 20145554221 is 12245554102.

It is a cyclic number.

It is not a de Polignac number, because 20145554221 - 2⁹ = 20145553709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20145554201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 336370 + ... + 391708.

It is an arithmetic number, because the mean of its divisors is an integer number (1391081580).

Almost surely, 2^20145554221 is an apocalyptic number.

It is an amenable number.

20145554221 is a deficient number, since it is larger than the sum of its proper divisors (2111751059).

20145554221 is a wasteful number, since it uses less digits than its factorization.

20145554221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56076.

The product of its (nonzero) digits is 16000, while the sum is 31.

The spelling of 20145554221 in words is "twenty billion, one hundred forty-five million, five hundred fifty-four thousand, two hundred twenty-one".