1671689957 has 4 divisors (see below), whose sum is σ = 1910502816. Its totient is φ = 1432877100.

The previous prime is 1671689953. The next prime is 1671689963. The reversal of 1671689957 is 7599861761.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7599861761 = 31 ⋅245156831.

It is a cyclic number.

It is not a de Polignac number, because 1671689957 - 2² = 1671689953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1671689896 and 1671689905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671689953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119406419 + ... + 119406432.

It is an arithmetic number, because the mean of its divisors is an integer number (477625704).

Almost surely, 2^1671689957 is an apocalyptic number.

It is an amenable number.

1671689957 is a deficient number, since it is larger than the sum of its proper divisors (238812859).

1671689957 is an equidigital number, since it uses as much as digits as its factorization.

1671689957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238812858.

The product of its digits is 5715360, while the sum is 59.

The square root of 1671689957 is about 40886.3052500467. The cubic root of 1671689957 is about 1186.8210606443.

The spelling of 1671689957 in words is "one billion, six hundred seventy-one million, six hundred eighty-nine thousand, nine hundred fifty-seven".