161777616 has 360 divisors, whose sum is σ = 589810464. Its totient is φ = 37739520.

The previous prime is 161777599. The next prime is 161777617. The reversal of 161777616 is 616777161.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161777617) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4372350 + ... + 4372386.

Almost surely, 2^161777616 is an apocalyptic number.

161777616 is a gapful number since it is divisible by the number (16) 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 161777616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294905232).

161777616 is an abundant number, since it is smaller than the sum of its proper divisors (428032848).

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

161777616 is a wasteful number, since it uses less digits than its factorization.

161777616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 73 counting only the distinct ones).

The product of its digits is 74088, while the sum is 42.

The square root of 161777616 is about 12719.1829926297. The cubic root of 161777616 is about 544.8866200752.

It can be divided in two parts, 161 and 777616, that added together give a palindrome (777777).

The spelling of 161777616 in words is "one hundred sixty-one million, seven hundred seventy-seven thousand, six hundred sixteen".