161850381 has 64 divisors (see below), whose sum is σ = 279552000. Its totient is φ = 82555200.

The previous prime is 161850371. The next prime is 161850383. The reversal of 161850381 is 183058161.

It is not a de Polignac number, because 161850381 - 2⁷ = 161850253 is a prime.

It is a super-2 number, since 2×161850381² = 52391091659690322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161850383) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 894111 + ... + 894291.

It is an arithmetic number, because the mean of its divisors is an integer number (4368000).

Almost surely, 2^161850381 is an apocalyptic number.

161850381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161850381 is a deficient number, since it is larger than the sum of its proper divisors (117701619).

161850381 is a wasteful number, since it uses less digits than its factorization.

161850381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 281 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 161850381 is about 12722.0431142171. The cubic root of 161850381 is about 544.9683016101.

The spelling of 161850381 in words is "one hundred sixty-one million, eight hundred fifty thousand, three hundred eighty-one".