20550040421 has 4 divisors (see below), whose sum is σ = 20631913344. Its totient is φ = 20468167500.

The previous prime is 20550040417. The next prime is 20550040451. The reversal of 20550040421 is 12404005502.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20550040421 - 2² = 20550040417 is a prime.

It is a super-2 number, since 2×20550040421² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20550040451) 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 3 ways as a sum of consecutive naturals, for example, 40936085 + ... + 40936586.

It is an arithmetic number, because the mean of its divisors is an integer number (5157978336).

Almost surely, 2^20550040421 is an apocalyptic number.

It is an amenable number.

20550040421 is a deficient number, since it is larger than the sum of its proper divisors (81872923).

20550040421 is an equidigital number, since it uses as much as digits as its factorization.

20550040421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81872922.

The product of its (nonzero) digits is 1600, while the sum is 23.

Adding to 20550040421 its reverse (12404005502), we get a palindrome (32954045923).

The spelling of 20550040421 in words is "twenty billion, five hundred fifty million, forty thousand, four hundred twenty-one".