161228840 has 32 divisors (see below), whose sum is σ = 366849000. Its totient is φ = 63765504.

The previous prime is 161228839. The next prime is 161228857. The reversal of 161228840 is 48822161.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 130736356 + 30492484 = 11434^2 + 5522^2 .

It is a junction number, because it is equal to n+sod(n) for n = 161228797 and 161228806.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19085 + ... + 26204.

Almost surely, 2^161228840 is an apocalyptic number.

161228840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161228840 is an abundant number, since it is smaller than the sum of its proper divisors (205620160).

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

161228840 is a wasteful number, since it uses less digits than its factorization.

161228840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45389 (or 45385 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 161228840 is about 12697.5918976789. The cubic root of 161228840 is about 544.2698074102.

The spelling of 161228840 in words is "one hundred sixty-one million, two hundred twenty-eight thousand, eight hundred forty".