13915561 has 4 divisors (see below), whose sum is σ = 15180624. Its totient is φ = 12650500.

The previous prime is 13915553. The next prime is 13915567. The reversal of 13915561 is 16551931.

13915561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13915561 - 2³ = 13915553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13915567) 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, 632515 + ... + 632536.

It is an arithmetic number, because the mean of its divisors is an integer number (3795156).

Almost surely, 2^13915561 is an apocalyptic number.

13915561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13915561 is a deficient number, since it is larger than the sum of its proper divisors (1265063).

13915561 is a wasteful number, since it uses less digits than its factorization.

13915561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1265062.

The product of its digits is 4050, while the sum is 31.

The square root of 13915561 is about 3730.3566853587. The cubic root of 13915561 is about 240.5287013549.

The spelling of 13915561 in words is "thirteen million, nine hundred fifteen thousand, five hundred sixty-one".