20550315421 has 4 divisors (see below), whose sum is σ = 20551096732. Its totient is φ = 20549534112.

The previous prime is 20550315419. The next prime is 20550315491. The reversal of 20550315421 is 12451305502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7190192025 + 13360123396 = 84795^2 + 115586^2 .

It is a cyclic number.

It is not a de Polignac number, because 20550315421 - 2¹ = 20550315419 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 20550315421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20550315491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 349776 + ... + 404281.

It is an arithmetic number, because the mean of its divisors is an integer number (5137774183).

Almost surely, 2^20550315421 is an apocalyptic number.

It is an amenable number.

20550315421 is a deficient number, since it is larger than the sum of its proper divisors (781311).

20550315421 is an equidigital number, since it uses as much as digits as its factorization.

20550315421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781310.

The product of its (nonzero) digits is 6000, while the sum is 28.

The spelling of 20550315421 in words is "twenty billion, five hundred fifty million, three hundred fifteen thousand, four hundred twenty-one".