161690893 has 32 divisors (see below), whose sum is σ = 221840640. Its totient is φ = 114048000.

The previous prime is 161690891. The next prime is 161690923. The reversal of 161690893 is 398096161.

It is a cyclic number.

It is not a de Polignac number, because 161690893 - 2¹ = 161690891 is a prime.

It is a super-2 number, since 2×161690893² = 52287889758274898, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161690891) 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 31 ways as a sum of consecutive naturals, for example, 26643 + ... + 32143.

It is an arithmetic number, because the mean of its divisors is an integer number (6932520).

Almost surely, 2^161690893 is an apocalyptic number.

161690893 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

161690893 is a deficient number, since it is larger than the sum of its proper divisors (60149747).

161690893 is a wasteful number, since it uses less digits than its factorization.

161690893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5557.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 161690893 is about 12715.7733937028. The cubic root of 161690893 is about 544.7892381469.

The spelling of 161690893 in words is "one hundred sixty-one million, six hundred ninety thousand, eight hundred ninety-three".