161690387 has 8 divisors (see below), whose sum is σ = 165881856. Its totient is φ = 157530312.

The previous prime is 161690381. The next prime is 161690393. The reversal of 161690387 is 783096161.

It is an interprime number because it is at equal distance from previous prime (161690381) and next prime (161690393).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161690387 - 2⁴ = 161690371 is a prime.

It is a super-2 number, since 2×161690387² = 52287562496419538, which contains 22 as substring.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161690381) 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 7 ways as a sum of consecutive naturals, for example, 2768 + ... + 18194.

It is an arithmetic number, because the mean of its divisors is an integer number (20735232).

Almost surely, 2^161690387 is an apocalyptic number.

161690387 is a deficient number, since it is larger than the sum of its proper divisors (4191469).

161690387 is a wasteful number, since it uses less digits than its factorization.

161690387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15697.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 161690387 is about 12715.7534971389. The cubic root of 161690387 is about 544.7886698534.

The spelling of 161690387 in words is "one hundred sixty-one million, six hundred ninety thousand, three hundred eighty-seven".