161977968 has 90 divisors (see below), whose sum is σ = 471029624. Its totient is φ = 53957664.

The previous prime is 161977919. The next prime is 161977969. The reversal of 161977968 is 869779161.

161977968 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161977969) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 104205 + ... + 105747.

Almost surely, 2^161977968 is an apocalyptic number.

161977968 is a gapful number since it is divisible by the number (18) 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 161977968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235514812).

161977968 is an abundant number, since it is smaller than the sum of its proper divisors (309051656).

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

161977968 is an frugal number, since it uses more digits than its factorization.

161977968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1575 (or 1548 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The square root of 161977968 is about 12727.0565332287. The cubic root of 161977968 is about 545.1114638892. Note that the first 3 decimals are identical.

The spelling of 161977968 in words is "one hundred sixty-one million, nine hundred seventy-seven thousand, nine hundred sixty-eight".