16115061521 has 8 divisors (see below), whose sum is σ = 17777967144. Its totient is φ = 14512625280.

The previous prime is 16115061497. The next prime is 16115061541. The reversal of 16115061521 is 12516051161.

It can be written as a sum of positive squares in 4 ways, for example, as 245360896 + 15869700625 = 15664^2 + 125975^2 .

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 16115061521 - 2¹⁸ = 16114799377 is a prime.

It is a super-2 number, since 2×16115061521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16115061541) 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, 15116786 + ... + 15117851.

It is an arithmetic number, because the mean of its divisors is an integer number (2222245893).

Almost surely, 2^16115061521 is an apocalyptic number.

It is an amenable number.

16115061521 is a deficient number, since it is larger than the sum of its proper divisors (1662905623).

16115061521 is a wasteful number, since it uses less digits than its factorization.

16115061521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30234691.

The product of its (nonzero) digits is 1800, while the sum is 29.

The spelling of 16115061521 in words is "sixteen billion, one hundred fifteen million, sixty-one thousand, five hundred twenty-one".