1660161640 has 16 divisors (see below), whose sum is σ = 3735363780. Its totient is φ = 664064640.

The previous prime is 1660161623. The next prime is 1660161641. The reversal of 1660161640 is 461610661.

It can be written as a sum of positive squares in 2 ways, for example, as 1415113924 + 245047716 = 37618^2 + 15654^2 .

It is a super-2 number, since 2×1660161640² = 5512273341854979200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1660161641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20751981 + ... + 20752060.

Almost surely, 2^1660161640 is an apocalyptic number.

1660161640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1660161640 is an abundant number, since it is smaller than the sum of its proper divisors (2075202140).

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

1660161640 is a wasteful number, since it uses less digits than its factorization.

1660161640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41504052 (or 41504048 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 1660161640 is about 40745.0811755235. The cubic root of 1660161640 is about 1184.0865779306.

The spelling of 1660161640 in words is "one billion, six hundred sixty million, one hundred sixty-one thousand, six hundred forty".