11721913397 has 2 divisors, whose sum is σ = 11721913398. Its totient is φ = 11721913396.

The previous prime is 11721913387. The next prime is 11721913417. The reversal of 11721913397 is 79331912711.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10446066436 + 1275846961 = 102206^2 + 35719^2 .

It is a cyclic number.

It is not a de Polignac number, because 11721913397 - 2¹⁶ = 11721847861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11721913327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5860956698 + 5860956699.

It is an arithmetic number, because the mean of its divisors is an integer number (5860956699).

Almost surely, 2^11721913397 is an apocalyptic number.

It is an amenable number.

11721913397 is a deficient number, since it is larger than the sum of its proper divisors (1).

11721913397 is an equidigital number, since it uses as much as digits as its factorization.

11721913397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 71442, while the sum is 44.

The spelling of 11721913397 in words is "eleven billion, seven hundred twenty-one million, nine hundred thirteen thousand, three hundred ninety-seven".