1671979857 has 4 divisors (see below), whose sum is σ = 2229306480. Its totient is φ = 1114653236.

The previous prime is 1671979853. The next prime is 1671979861. The reversal of 1671979857 is 7589791761.

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: 7589791761 = 3 ⋅2529930587.

It is an interprime number because it is at equal distance from previous prime (1671979853) and next prime (1671979861).

It is a cyclic number.

It is not a de Polignac number, because 1671979857 - 2² = 1671979853 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1671979857.

It is not an unprimeable number, because it can be changed into a prime (1671979853) 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, 278663307 + ... + 278663312.

It is an arithmetic number, because the mean of its divisors is an integer number (557326620).

Almost surely, 2^1671979857 is an apocalyptic number.

It is an amenable number.

1671979857 is a deficient number, since it is larger than the sum of its proper divisors (557326623).

1671979857 is an equidigital number, since it uses as much as digits as its factorization.

1671979857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557326622.

The product of its digits is 6667920, while the sum is 60.

The square root of 1671979857 is about 40889.8502931962. The cubic root of 1671979857 is about 1186.8896617900.

The spelling of 1671979857 in words is "one billion, six hundred seventy-one million, nine hundred seventy-nine thousand, eight hundred fifty-seven".