20005555501 has 2 divisors, whose sum is σ = 20005555502. Its totient is φ = 20005555500.

The previous prime is 20005555439. The next prime is 20005555519. The reversal of 20005555501 is 10555550002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12028386276 + 7977169225 = 109674^2 + 89315^2 .

It is a cyclic number.

It is not a de Polignac number, because 20005555501 - 2¹¹ = 20005553453 is a prime.

It is a super-2 number, since 2×20005555501² (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 20005555501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20005555541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10002777750 + 10002777751.

It is an arithmetic number, because the mean of its divisors is an integer number (10002777751).

Almost surely, 2^20005555501 is an apocalyptic number.

It is an amenable number.

20005555501 is a deficient number, since it is larger than the sum of its proper divisors (1).

20005555501 is an equidigital number, since it uses as much as digits as its factorization.

20005555501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6250, while the sum is 28.

The spelling of 20005555501 in words is "twenty billion, five million, five hundred fifty-five thousand, five hundred one".