161693537 has 2 divisors, whose sum is σ = 161693538. Its totient is φ = 161693536.

The previous prime is 161693491. The next prime is 161693549. The reversal of 161693537 is 735396161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127599616 + 34093921 = 11296^2 + 5839^2 .

It is an emirp because it is prime and its reverse (735396161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161693537 - 2²² = 157499233 is a prime.

It is a super-2 number, since 2×161693537² = 52289599815140738, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161693494 and 161693503.

It is not a weakly prime, because it can be changed into another prime (161690537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80846768 + 80846769.

It is an arithmetic number, because the mean of its divisors is an integer number (80846769).

Almost surely, 2^161693537 is an apocalyptic number.

It is an amenable number.

161693537 is a deficient number, since it is larger than the sum of its proper divisors (1).

161693537 is an equidigital number, since it uses as much as digits as its factorization.

161693537 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102060, while the sum is 41.

The square root of 161693537 is about 12715.8773586410. The cubic root of 161693537 is about 544.7922076295.

The spelling of 161693537 in words is "one hundred sixty-one million, six hundred ninety-three thousand, five hundred thirty-seven".