11225251991 has 2 divisors, whose sum is σ = 11225251992. Its totient is φ = 11225251990.

The previous prime is 11225251981. The next prime is 11225252029. The reversal of 11225251991 is 19915252211.

It is an a-pointer prime, because the next prime (11225252029) can be obtained adding 11225251991 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11225251991 - 2²⁶ = 11158143127 is a prime.

It is a super-2 number, since 2×11225251991² (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 (11225251981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5612625995 + 5612625996.

It is an arithmetic number, because the mean of its divisors is an integer number (5612625996).

Almost surely, 2^11225251991 is an apocalyptic number.

11225251991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11225251991 is an equidigital number, since it uses as much as digits as its factorization.

11225251991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16200, while the sum is 38.

The spelling of 11225251991 in words is "eleven billion, two hundred twenty-five million, two hundred fifty-one thousand, nine hundred ninety-one".