20354580621 has 12 divisors (see below), whose sum is σ = 29402530300. Its totient is φ = 13569042240.

The previous prime is 20354580619. The next prime is 20354580647. The reversal of 20354580621 is 12608545302.

20354580621 is a `hidden beast` number, since 2 + 0 + 3 + 54 + 580 + 6 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11998792521 + 8355788100 = 109539^2 + 91410^2 .

It is not a de Polignac number, because 20354580621 - 2¹ = 20354580619 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20354580611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190305 + ... + 277353.

Almost surely, 2^20354580621 is an apocalyptic number.

It is an amenable number.

20354580621 is a deficient number, since it is larger than the sum of its proper divisors (9047949679).

20354580621 is a wasteful number, since it uses less digits than its factorization.

20354580621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113036 (or 113033 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 20354580621 in words is "twenty billion, three hundred fifty-four million, five hundred eighty thousand, six hundred twenty-one".