16215125985 has 24 divisors (see below), whose sum is σ = 28109773224. Its totient is φ = 8646973440.

The previous prime is 16215125951. The next prime is 16215125987. The reversal of 16215125985 is 58952151261.

16215125985 is a `hidden beast` number, since 1 + 6 + 2 + 1 + 51 + 2 + 598 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7150562721 + 9064563264 = 84561^2 + 95208^2 .

It is not a de Polignac number, because 16215125985 - 2⁹ = 16215125473 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 16215125985.

It is not an unprimeable number, because it can be changed into a prime (16215125987) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 440449 + ... + 475841.

It is an arithmetic number, because the mean of its divisors is an integer number (1171240551).

Almost surely, 2^16215125985 is an apocalyptic number.

16215125985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16215125985 is a deficient number, since it is larger than the sum of its proper divisors (11894647239).

16215125985 is a wasteful number, since it uses less digits than its factorization.

16215125985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45585 (or 45582 counting only the distinct ones).

The product of its digits is 216000, while the sum is 45.

The spelling of 16215125985 in words is "sixteen billion, two hundred fifteen million, one hundred twenty-five thousand, nine hundred eighty-five".