161684537 has 16 divisors (see below), whose sum is σ = 189298944. Its totient is φ = 135240000.

The previous prime is 161684527. The next prime is 161684573. The reversal of 161684537 is 735486161.

It is not a de Polignac number, because 161684537 - 2⁴ = 161684521 is a prime.

It is a super-2 number, since 2×161684537² = 52283779009808738, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161684494 and 161684503.

It is not an unprimeable number, because it can be changed into a prime (161684507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48587 + ... + 51807.

It is an arithmetic number, because the mean of its divisors is an integer number (11831184).

Almost surely, 2^161684537 is an apocalyptic number.

It is an amenable number.

161684537 is a deficient number, since it is larger than the sum of its proper divisors (27614407).

161684537 is a wasteful number, since it uses less digits than its factorization.

161684537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3400.

The product of its digits is 120960, while the sum is 41.

The square root of 161684537 is about 12715.5234654339. The cubic root of 161684537 is about 544.7820995759.

The spelling of 161684537 in words is "one hundred sixty-one million, six hundred eighty-four thousand, five hundred thirty-seven".