13771561 has 8 divisors (see below), whose sum is σ = 14530880. Its totient is φ = 13015728.

The previous prime is 13771559. The next prime is 13771577. The reversal of 13771561 is 16517731.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13771561 - 2¹ = 13771559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13771661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13315 + ... + 14311.

It is an arithmetic number, because the mean of its divisors is an integer number (1816360).

Almost surely, 2^13771561 is an apocalyptic number.

It is an amenable number.

13771561 is a deficient number, since it is larger than the sum of its proper divisors (759319).

13771561 is an equidigital number, since it uses as much as digits as its factorization.

13771561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1743.

The product of its digits is 4410, while the sum is 31.

The square root of 13771561 is about 3711.0053893790. The cubic root of 13771561 is about 239.6961490380.

The spelling of 13771561 in words is "thirteen million, seven hundred seventy-one thousand, five hundred sixty-one".