11211987461 has 2 divisors, whose sum is σ = 11211987462. Its totient is φ = 11211987460.

The previous prime is 11211987439. The next prime is 11211987463. The reversal of 11211987461 is 16478911211.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11002751236 + 209236225 = 104894^2 + 14465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11211987461 is a prime.

Together with 11211987463, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11211987463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5605993730 + 5605993731.

It is an arithmetic number, because the mean of its divisors is an integer number (5605993731).

Almost surely, 2^11211987461 is an apocalyptic number.

It is an amenable number.

11211987461 is a deficient number, since it is larger than the sum of its proper divisors (1).

11211987461 is an equidigital number, since it uses as much as digits as its factorization.

11211987461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 41.

The spelling of 11211987461 in words is "eleven billion, two hundred eleven million, nine hundred eighty-seven thousand, four hundred sixty-one".