161354778 has 48 divisors (see below), whose sum is σ = 351482976. Its totient is φ = 49358400.

The previous prime is 161354773. The next prime is 161354779. The reversal of 161354778 is 877453161.

It is not an unprimeable number, because it can be changed into a prime (161354773) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 229828 + ... + 230528.

It is an arithmetic number, because the mean of its divisors is an integer number (7322562).

Almost surely, 2^161354778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161354778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (175741488).

161354778 is an abundant number, since it is smaller than the sum of its proper divisors (190128198).

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

161354778 is a wasteful number, since it uses less digits than its factorization.

161354778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 959 (or 946 counting only the distinct ones).

The product of its digits is 141120, while the sum is 42.

The square root of 161354778 is about 12702.5500589449. The cubic root of 161354778 is about 544.4114826667.

The spelling of 161354778 in words is "one hundred sixty-one million, three hundred fifty-four thousand, seven hundred seventy-eight".