161701785 has 64 divisors (see below), whose sum is σ = 331200000. Its totient is φ = 73322496.

The previous prime is 161701783. The next prime is 161701811. The reversal of 161701785 is 587107161.

It is a happy number.

It is not a de Polignac number, because 161701785 - 2¹ = 161701783 is a prime.

It is a super-2 number, since 2×161701785² = 52294934544372450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161701783) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 128841 + ... + 130089.

It is an arithmetic number, because the mean of its divisors is an integer number (5175000).

Almost surely, 2^161701785 is an apocalyptic number.

161701785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161701785 is an abundant number, since it is smaller than the sum of its proper divisors (169498215).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161701785 is a wasteful number, since it uses less digits than its factorization.

161701785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1407 (or 1401 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 36.

The square root of 161701785 is about 12716.2016734558. The cubic root of 161701785 is about 544.8014707698.

It can be divided in two parts, 16170 and 1785, that added together give a triangular number (17955 = T₁₈₉).

The spelling of 161701785 in words is "one hundred sixty-one million, seven hundred one thousand, seven hundred eighty-five".