161236156500 has 384 divisors, whose sum is σ = 552160627200. Its totient is φ = 40509849600.

The previous prime is 161236156453. The next prime is 161236156513. The reversal of 161236156500 is 5651632161.

161236156500 is a `hidden beast` number, since 1 + 61 + 2 + 36 + 1 + 565 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 49502872 + ... + 49506128.

It is an arithmetic number, because the mean of its divisors is an integer number (1437918300).

Almost surely, 2^161236156500 is an apocalyptic number.

161236156500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161236156500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276080313600).

161236156500 is an abundant number, since it is smaller than the sum of its proper divisors (390924470700).

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

161236156500 is a wasteful number, since it uses less digits than its factorization.

161236156500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3497 (or 3479 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

Adding to 161236156500 its reverse (5651632161), we get a palindrome (166887788661).

The spelling of 161236156500 in words is "one hundred sixty-one billion, two hundred thirty-six million, one hundred fifty-six thousand, five hundred".