161598788505 has 256 divisors, whose sum is σ = 380806963200. Its totient is φ = 62985600000.

The previous prime is 161598788501. The next prime is 161598788563. The reversal of 161598788505 is 505887895161.

161598788505 is a `hidden beast` number, since 1 + 6 + 1 + 59 + 8 + 78 + 8 + 505 = 666.

It is not a de Polignac number, because 161598788505 - 2² = 161598788501 is a prime.

It is a super-2 number, since 2×161598788505² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (161598788501) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 19943955 + ... + 19952055.

It is an arithmetic number, because the mean of its divisors is an integer number (1487527200).

Almost surely, 2^161598788505 is an apocalyptic number.

161598788505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161598788505 is an abundant number, since it is smaller than the sum of its proper divisors (219208174695).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161598788505 is a wasteful number, since it uses less digits than its factorization.

161598788505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8253 (or 8247 counting only the distinct ones).

The product of its (nonzero) digits is 24192000, while the sum is 63.

The spelling of 161598788505 in words is "one hundred sixty-one billion, five hundred ninety-eight million, seven hundred eighty-eight thousand, five hundred five".