1620172112985 has 64 divisors (see below), whose sum is σ = 2921780160000. Its totient is φ = 851657103360.

The previous prime is 1620172112947. The next prime is 1620172113029. The reversal of 1620172112985 is 5892112710261.

1620172112985 is a `hidden beast` number, since 1 + 620 + 1 + 7 + 2 + 1 + 12 + 9 + 8 + 5 = 666.

It is not a de Polignac number, because 1620172112985 - 2¹¹ = 1620172110937 is a prime.

It is a super-2 number, since 2×1620172112985² (a number of 25 digits) contains 22 as substring.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1620172112985.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 33034161 + ... + 33083169.

It is an arithmetic number, because the mean of its divisors is an integer number (45652815000).

Almost surely, 2^{1620172112985} is an apocalyptic number.

1620172112985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1620172112985 is a deficient number, since it is larger than the sum of its proper divisors (1301608047015).

1620172112985 is a wasteful number, since it uses less digits than its factorization.

1620172112985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52543 (or 52537 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 45.

The spelling of 1620172112985 in words is "one trillion, six hundred twenty billion, one hundred seventy-two million, one hundred twelve thousand, nine hundred eighty-five".