11501551 has 2 divisors, whose sum is σ = 11501552. Its totient is φ = 11501550.

The previous prime is 11501549. The next prime is 11501557. The reversal of 11501551 is 15510511.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11501551 - 2¹ = 11501549 is a prime.

Together with 11501549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11501557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5750775 + 5750776.

It is an arithmetic number, because the mean of its divisors is an integer number (5750776).

Almost surely, 2^11501551 is an apocalyptic number.

11501551 is a deficient number, since it is larger than the sum of its proper divisors (1).

11501551 is an equidigital number, since it uses as much as digits as its factorization.

11501551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 125, while the sum is 19.

The square root of 11501551 is about 3391.3936663266. The cubic root of 11501551 is about 225.7280188079.

It can be divided in two parts, 1150 and 1551, that added together give a triangular number (2701 = T₇₃).

The spelling of 11501551 in words is "eleven million, five hundred one thousand, five hundred fifty-one".