161001065500 has 48 divisors (see below), whose sum is σ = 383592369888. Its totient is φ = 58545840000.

The previous prime is 161001065473. The next prime is 161001065501. The reversal of 161001065500 is 5560100161.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161001065501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14630961 + ... + 14641960.

It is an arithmetic number, because the mean of its divisors is an integer number (7991507706).

Almost surely, 2^161001065500 is an apocalyptic number.

161001065500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161001065500 is an abundant number, since it is smaller than the sum of its proper divisors (222591304388).

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

161001065500 is a wasteful number, since it uses less digits than its factorization.

161001065500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29272951 (or 29272939 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 25.

Adding to 161001065500 its reverse (5560100161), we get a palindrome (166561165661).

It can be divided in two parts, 16100 and 1065500, that added together give a square (1081600 = 1040²).

The spelling of 161001065500 in words is "one hundred sixty-one billion, one million, sixty-five thousand, five hundred".