161213140 has 36 divisors (see below), whose sum is σ = 372128148. Its totient is φ = 58622080.

The previous prime is 161213111. The next prime is 161213201. The reversal of 161213140 is 41312161.

It can be written as a sum of positive squares in 2 ways, for example, as 16924996 + 144288144 = 4114^2 + 12012^2 .

It is a congruent number.

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, 30889 + ... + 35728.

It is an arithmetic number, because the mean of its divisors is an integer number (10336893).

Almost surely, 2^161213140 is an apocalyptic number.

161213140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161213140 is an abundant number, since it is smaller than the sum of its proper divisors (210915008).

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

161213140 is a wasteful number, since it uses less digits than its factorization.

161213140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66648 (or 66635 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 161213140 is about 12696.9736551668. The cubic root of 161213140 is about 544.2521403614.

The spelling of 161213140 in words is "one hundred sixty-one million, two hundred thirteen thousand, one hundred forty".