11503561 has 2 divisors, whose sum is σ = 11503562. Its totient is φ = 11503560.

The previous prime is 11503553. The next prime is 11503567. The reversal of 11503561 is 16530511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10791225 + 712336 = 3285^2 + 844^2 .

It is a cyclic number.

It is not a de Polignac number, because 11503561 - 2³ = 11503553 is a prime.

It is not a weakly prime, because it can be changed into another prime (11503567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5751780 + 5751781.

It is an arithmetic number, because the mean of its divisors is an integer number (5751781).

Almost surely, 2^11503561 is an apocalyptic number.

It is an amenable number.

11503561 is a deficient number, since it is larger than the sum of its proper divisors (1).

11503561 is an equidigital number, since it uses as much as digits as its factorization.

11503561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 11503561 is about 3391.6899917298. The cubic root of 11503561 is about 225.7411673792.

The spelling of 11503561 in words is "eleven million, five hundred three thousand, five hundred sixty-one".