11421647581 has 2 divisors, whose sum is σ = 11421647582. Its totient is φ = 11421647580.

The previous prime is 11421647563. The next prime is 11421647621. The reversal of 11421647581 is 18574612411.

It is an a-pointer prime, because the next prime (11421647621) can be obtained adding 11421647581 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7657825081 + 3763822500 = 87509^2 + 61350^2 .

It is an emirp because it is prime and its reverse (18574612411) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11421647581 - 2⁷ = 11421647453 is a prime.

It is a super-2 number, since 2×11421647581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11421647561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5710823790 + 5710823791.

It is an arithmetic number, because the mean of its divisors is an integer number (5710823791).

Almost surely, 2^11421647581 is an apocalyptic number.

It is an amenable number.

11421647581 is a deficient number, since it is larger than the sum of its proper divisors (1).

11421647581 is an equidigital number, since it uses as much as digits as its factorization.

11421647581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 53760, while the sum is 40.

The spelling of 11421647581 in words is "eleven billion, four hundred twenty-one million, six hundred forty-seven thousand, five hundred eighty-one".