16405681525 has 12 divisors (see below), whose sum is σ = 20349016900. Its totient is φ = 13120692480.

The previous prime is 16405681459. The next prime is 16405681543. The reversal of 16405681525 is 52518650461.

It can be written as a sum of positive squares in 6 ways, for example, as 1629091044 + 14776590481 = 40362^2 + 121559^2 .

It is not a de Polignac number, because 16405681525 - 2⁹ = 16405681013 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7860 + ... + 181309.

Almost surely, 2^16405681525 is an apocalyptic number.

It is an amenable number.

16405681525 is a deficient number, since it is larger than the sum of its proper divisors (3943335375).

16405681525 is a wasteful number, since it uses less digits than its factorization.

16405681525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192648 (or 192643 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 43.

The spelling of 16405681525 in words is "sixteen billion, four hundred five million, six hundred eighty-one thousand, five hundred twenty-five".