13416820561 has 3 divisors (see below), whose sum is σ = 13416936393. Its totient is φ = 13416704730.

The previous prime is 13416820519. The next prime is 13416820609. The reversal of 13416820561 is 16502861431.

It is a happy number.

The square root of 13416820561 is 115831.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 13416820561 - 2³¹ = 11269336913 is a prime.

It is a super-2 number, since 2×13416820561² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13416820561.

It is not an unprimeable number, because it can be changed into a prime (13416820511) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 57916 + ... + 173746.

It is an arithmetic number, because the mean of its divisors is an integer number (4472312131).

Almost surely, 2^13416820561 is an apocalyptic number.

13416820561 is the 115831-st square number.

13416820561 is the 57916-th centered octagonal number.

It is an amenable number.

13416820561 is a deficient number, since it is larger than the sum of its proper divisors (115832).

13416820561 is an frugal number, since it uses more digits than its factorization.

13416820561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231662 (or 115831 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The spelling of 13416820561 in words is "thirteen billion, four hundred sixteen million, eight hundred twenty thousand, five hundred sixty-one".