1661271071 has 24 divisors (see below), whose sum is σ = 1792781760. Its totient is φ = 1538450496.

The previous prime is 1661271067. The next prime is 1661271091. The reversal of 1661271071 is 1701721661.

It is not a de Polignac number, because 1661271071 - 2² = 1661271067 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661271091) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2709761 + ... + 2710373.

It is an arithmetic number, because the mean of its divisors is an integer number (74699240).

Almost surely, 2^1661271071 is an apocalyptic number.

1661271071 is a deficient number, since it is larger than the sum of its proper divisors (131510689).

1661271071 is a wasteful number, since it uses less digits than its factorization.

1661271071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815 (or 792 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 32.

The square root of 1661271071 is about 40758.6931954399. The cubic root of 1661271071 is about 1184.3502811363.

The spelling of 1661271071 in words is "one billion, six hundred sixty-one million, two hundred seventy-one thousand, seventy-one".