161432381 has 8 divisors (see below), whose sum is σ = 176619744. Its totient is φ = 146330320.

The previous prime is 161432351. The next prime is 161432389. The reversal of 161432381 is 183234161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161432381 - 2¹⁰ = 161431357 is a prime.

It is a super-2 number, since 2×161432381² = 52120827270658322, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161432389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17330 + ... + 24963.

It is an arithmetic number, because the mean of its divisors is an integer number (22077468).

Almost surely, 2^161432381 is an apocalyptic number.

161432381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161432381 is a deficient number, since it is larger than the sum of its proper divisors (15187363).

161432381 is a wasteful number, since it uses less digits than its factorization.

161432381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42651.

The product of its digits is 3456, while the sum is 29.

The square root of 161432381 is about 12705.6043146322. The cubic root of 161432381 is about 544.4987462599.

The spelling of 161432381 in words is "one hundred sixty-one million, four hundred thirty-two thousand, three hundred eighty-one".