11611211621 has 2 divisors, whose sum is σ = 11611211622. Its totient is φ = 11611211620.

The previous prime is 11611211587. The next prime is 11611211641. The reversal of 11611211621 is 12611211611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8431830625 + 3179380996 = 91825^2 + 56386^2 .

It is an emirp because it is prime and its reverse (12611211611) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11611211621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11611211641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5805605810 + 5805605811.

It is an arithmetic number, because the mean of its divisors is an integer number (5805605811).

Almost surely, 2^11611211621 is an apocalyptic number.

It is an amenable number.

11611211621 is a deficient number, since it is larger than the sum of its proper divisors (1).

11611211621 is an equidigital number, since it uses as much as digits as its factorization.

11611211621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 23.

The spelling of 11611211621 in words is "eleven billion, six hundred eleven million, two hundred eleven thousand, six hundred twenty-one".