20550435430021 has 12 divisors (see below), whose sum is σ = 23908319143500. Its totient is φ = 17612661669120.

The previous prime is 20550435430013. The next prime is 20550435430037. The reversal of 20550435430021 is 12003453405502.

It can be written as a sum of positive squares in 2 ways, for example, as 16078183277121 + 4472252152900 = 4009761^2 + 2114770^2 .

It is not a de Polignac number, because 20550435430021 - 2³ = 20550435430013 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 (20550435430121) 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, 23340396 + ... + 24204853.

It is an arithmetic number, because the mean of its divisors is an integer number (1992359928625).

Almost surely, 2^{20550435430021} is an apocalyptic number.

It is an amenable number.

20550435430021 is a deficient number, since it is larger than the sum of its proper divisors (3357883713479).

20550435430021 is an equidigital number, since it uses as much as digits as its factorization.

20550435430021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47554084 (or 47554077 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 34.

Adding to 20550435430021 its reverse (12003453405502), we get a palindrome (32553888835523).

The spelling of 20550435430021 in words is "twenty trillion, five hundred fifty billion, four hundred thirty-five million, four hundred thirty thousand, twenty-one".