1661386071 has 16 divisors (see below), whose sum is σ = 2355111936. Its totient is φ = 1039442976.

The previous prime is 1661386063. The next prime is 1661386109. The reversal of 1661386071 is 1706831661.

It is not a de Polignac number, because 1661386071 - 2³ = 1661386063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661386021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 223495 + ... + 230808.

It is an arithmetic number, because the mean of its divisors is an integer number (147194496).

Almost surely, 2^1661386071 is an apocalyptic number.

1661386071 is a deficient number, since it is larger than the sum of its proper divisors (693725865).

1661386071 is a wasteful number, since it uses less digits than its factorization.

1661386071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454382.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 1661386071 is about 40760.1039130177. The cubic root of 1661386071 is about 1184.3776090344.

The spelling of 1661386071 in words is "one billion, six hundred sixty-one million, three hundred eighty-six thousand, seventy-one".