1671661761 has 32 divisors (see below), whose sum is σ = 2874700800. Its totient is φ = 838447680.

The previous prime is 1671661727. The next prime is 1671661801.

1671661761 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1671661761 - 2⁷ = 1671661633 is a prime.

It is a super-2 number, since 2×1671661761² = 5588906086379242242, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1671661721) 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 31 ways as a sum of consecutive naturals, for example, 118071 + ... + 131468.

It is an arithmetic number, because the mean of its divisors is an integer number (89834400).

Almost surely, 2^1671661761 is an apocalyptic number.

1671661761 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1671661761 is a deficient number, since it is larger than the sum of its proper divisors (1203039039).

1671661761 is a wasteful number, since it uses less digits than its factorization.

1671661761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249589.

The product of its digits is 63504, while the sum is 42.

The square root of 1671661761 is about 40885.9604387619. The cubic root of 1671661761 is about 1186.8143879966.

The spelling of 1671661761 in words is "one billion, six hundred seventy-one million, six hundred sixty-one thousand, seven hundred sixty-one".