161960381 has 4 divisors (see below), whose sum is σ = 176684064. Its totient is φ = 147236700.

The previous prime is 161960371. The next prime is 161960387. The reversal of 161960381 is 183069161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161960381 is a prime.

It is a super-2 number, since 2×161960381² = 52462330027330322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161960387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7361825 + ... + 7361846.

It is an arithmetic number, because the mean of its divisors is an integer number (44171016).

Almost surely, 2^161960381 is an apocalyptic number.

161960381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161960381 is a deficient number, since it is larger than the sum of its proper divisors (14723683).

161960381 is a wasteful number, since it uses less digits than its factorization.

161960381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14723682.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 161960381 is about 12726.3655848793. The cubic root of 161960381 is about 545.0917344111.

The spelling of 161960381 in words is "one hundred sixty-one million, nine hundred sixty thousand, three hundred eighty-one".