21611167711421 has 4 divisors (see below), whose sum is σ = 21611600616672. Its totient is φ = 21610734806172.

The previous prime is 21611167711417. The next prime is 21611167711423. The reversal of 21611167711421 is 12411776111612.

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 21611167711421 - 2² = 21611167711417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611167711423) 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, 216377735 + ... + 216477588.

It is an arithmetic number, because the mean of its divisors is an integer number (5402900154168).

Almost surely, 2^{21611167711421} is an apocalyptic number.

It is an amenable number.

21611167711421 is a deficient number, since it is larger than the sum of its proper divisors (432905251).

21611167711421 is an equidigital number, since it uses as much as digits as its factorization.

21611167711421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432905250.

The product of its digits is 28224, while the sum is 41.

The spelling of 21611167711421 in words is "twenty-one trillion, six hundred eleven billion, one hundred sixty-seven million, seven hundred eleven thousand, four hundred twenty-one".