21555025040011 has 4 divisors (see below), whose sum is σ = 21555055359792. Its totient is φ = 21554994720232.

The previous prime is 21555025039981. The next prime is 21555025040053. The reversal of 21555025040011 is 11004052055512.

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

It is a cyclic number.

It is not a de Polignac number, because 21555025040011 - 2⁷ = 21555025039883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21555025040111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14067256 + ... + 15524101.

It is an arithmetic number, because the mean of its divisors is an integer number (5388763839948).

Almost surely, 2^{21555025040011} is an apocalyptic number.

21555025040011 is a deficient number, since it is larger than the sum of its proper divisors (30319781).

21555025040011 is an equidigital number, since it uses as much as digits as its factorization.

21555025040011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30319780.

The product of its (nonzero) digits is 10000, while the sum is 31.

Adding to 21555025040011 its reverse (11004052055512), we get a palindrome (32559077095523).

The spelling of 21555025040011 in words is "twenty-one trillion, five hundred fifty-five billion, twenty-five million, forty thousand, eleven".