20005551001 has 2 divisors, whose sum is σ = 20005551002. Its totient is φ = 20005551000.

The previous prime is 20005550977. The next prime is 20005551011. The reversal of 20005551001 is 10015550002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16978350601 + 3027200400 = 130301^2 + 55020^2 .

It is a cyclic number.

It is not a de Polignac number, because 20005551001 - 2³³ = 11415616409 is a prime.

It is a super-2 number, since 2×20005551001² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20005551001.

It is not a weakly prime, because it can be changed into another prime (20005551011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10002775500 + 10002775501.

It is an arithmetic number, because the mean of its divisors is an integer number (10002775501).

Almost surely, 2^20005551001 is an apocalyptic number.

It is an amenable number.

20005551001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20005551001 is an equidigital number, since it uses as much as digits as its factorization.

20005551001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 250, while the sum is 19.

Subtracting from 20005551001 its reverse (10015550002), we obtain a palindrome (9990000999).

The spelling of 20005551001 in words is "twenty billion, five million, five hundred fifty-one thousand, one".