161631441 has 6 divisors (see below), whose sum is σ = 233467650. Its totient is φ = 107754288.

The previous prime is 161631433. The next prime is 161631467. The reversal of 161631441 is 144136161.

161631441 is a `hidden beast` number, since 1 + 616 + 3 + 1 + 4 + 41 = 666.

It can be written as a sum of positive squares in only one way, i.e., 106812225 + 54819216 = 10335^2 + 7404^2 .

It is not a de Polignac number, because 161631441 - 2³ = 161631433 is a prime.

It is a super-2 number, since 2×161631441² = 52249445439472962, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161631541) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8979516 + ... + 8979533.

It is an arithmetic number, because the mean of its divisors is an integer number (38911275).

Almost surely, 2^161631441 is an apocalyptic number.

It is an amenable number.

161631441 is a deficient number, since it is larger than the sum of its proper divisors (71836209).

161631441 is a wasteful number, since it uses less digits than its factorization.

161631441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17959055 (or 17959052 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 161631441 is about 12713.4354523079. The cubic root of 161631441 is about 544.7224589163.

The spelling of 161631441 in words is "one hundred sixty-one million, six hundred thirty-one thousand, four hundred forty-one".