11781487 has 4 divisors (see below), whose sum is σ = 11823696. Its totient is φ = 11739280.

The previous prime is 11781461. The next prime is 11781521. The reversal of 11781487 is 78418711.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78418711 = 7 ⋅11202673.

It is a cyclic number.

It is not a de Polignac number, because 11781487 - 2¹⁵ = 11748719 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11781787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20683 + ... + 21244.

It is an arithmetic number, because the mean of its divisors is an integer number (2955924).

Almost surely, 2^11781487 is an apocalyptic number.

11781487 is a deficient number, since it is larger than the sum of its proper divisors (42209).

11781487 is an equidigital number, since it uses as much as digits as its factorization.

11781487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42208.

The product of its digits is 12544, while the sum is 37.

The square root of 11781487 is about 3432.4170783866. The cubic root of 11781487 is about 227.5446887213.

The spelling of 11781487 in words is "eleven million, seven hundred eighty-one thousand, four hundred eighty-seven".