11420897981 has 2 divisors, whose sum is σ = 11420897982. Its totient is φ = 11420897980.

The previous prime is 11420897933. The next prime is 11420898011. The reversal of 11420897981 is 18979802411.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11223495481 + 197402500 = 105941^2 + 14050^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11420897981 is a prime.

It is a super-2 number, since 2×11420897981² (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 (11420897281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5710448990 + 5710448991.

It is an arithmetic number, because the mean of its divisors is an integer number (5710448991).

Almost surely, 2^11420897981 is an apocalyptic number.

It is an amenable number.

11420897981 is a deficient number, since it is larger than the sum of its proper divisors (1).

11420897981 is an equidigital number, since it uses as much as digits as its factorization.

11420897981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 50.

The spelling of 11420897981 in words is "eleven billion, four hundred twenty million, eight hundred ninety-seven thousand, nine hundred eighty-one".