21545701011011 has 4 divisors (see below), whose sum is σ = 21546013332024. Its totient is φ = 21545388690000.

The previous prime is 21545701011007. The next prime is 21545701011013. The reversal of 21545701011011 is 11011010754512.

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 21545701011011 - 2² = 21545701011007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21545701011013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156057005 + ... + 156195006.

It is an arithmetic number, because the mean of its divisors is an integer number (5386503333006).

Almost surely, 2^{21545701011011} is an apocalyptic number.

21545701011011 is a deficient number, since it is larger than the sum of its proper divisors (312321013).

21545701011011 is an equidigital number, since it uses as much as digits as its factorization.

21545701011011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312321012.

The product of its (nonzero) digits is 1400, while the sum is 29.

Adding to 21545701011011 its reverse (11011010754512), we get a palindrome (32556711765523).

The spelling of 21545701011011 in words is "twenty-one trillion, five hundred forty-five billion, seven hundred one million, eleven thousand, eleven".