161663481 has 96 divisors (see below), whose sum is σ = 297123840. Its totient is φ = 82684800.

The previous prime is 161663479. The next prime is 161663497. The reversal of 161663481 is 184366161.

161663481 is a `hidden beast` number, since 1 + 6 + 16 + 634 + 8 + 1 = 666.

It is not a de Polignac number, because 161663481 - 2¹ = 161663479 is a prime.

It is a super-2 number, since 2×161663481² = 52270162178074722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161663441) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2650191 + ... + 2650251.

It is an arithmetic number, because the mean of its divisors is an integer number (3095040).

Almost surely, 2^161663481 is an apocalyptic number.

It is an amenable number.

161663481 is a deficient number, since it is larger than the sum of its proper divisors (135460359).

161663481 is a wasteful number, since it uses less digits than its factorization.

161663481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187 (or 184 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 161663481 is about 12714.6954741354. The cubic root of 161663481 is about 544.7584497574.

The spelling of 161663481 in words is "one hundred sixty-one million, six hundred sixty-three thousand, four hundred eighty-one".