161245440 has 108 divisors (see below), whose sum is σ = 557932284. Its totient is φ = 42995712.

The previous prime is 161245439. The next prime is 161245499. The reversal of 161245440 is 44542161.

161245440 is a `hidden beast` number, since 1 + 612 + 4 + 5 + 4 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 68161536 + 93083904 = 8256^2 + 9648^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4522 + ... + 18518.

Almost surely, 2^161245440 is an apocalyptic number.

161245440 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 161245440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (278966142).

161245440 is an abundant number, since it is smaller than the sum of its proper divisors (396686844).

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

161245440 is a wasteful number, since it uses less digits than its factorization.

161245440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14024 (or 14007 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 161245440 is about 12698.2455481062. The cubic root of 161245440 is about 544.2884859724.

It can be divided in two parts, 16 and 1245440, that added together give a square (1245456 = 1116²).

The spelling of 161245440 in words is "one hundred sixty-one million, two hundred forty-five thousand, four hundred forty".