7857971 has 4 divisors (see below), whose sum is σ = 8572344. Its totient is φ = 7143600.

The previous prime is 7857953. The next prime is 7857979. The reversal of 7857971 is 1797587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1797587 = 11 ⋅163417.

It is a cyclic number.

It is not a de Polignac number, because 7857971 - 2¹⁸ = 7595827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7857979) 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, 357170 + ... + 357191.

It is an arithmetic number, because the mean of its divisors is an integer number (2143086).

Almost surely, 2^7857971 is an apocalyptic number.

7857971 is a deficient number, since it is larger than the sum of its proper divisors (714373).

7857971 is a wasteful number, since it uses less digits than its factorization.

7857971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714372.

The product of its digits is 123480, while the sum is 44.

The square root of 7857971 is about 2803.2072702531. The cubic root of 7857971 is about 198.8093508389.

The spelling of 7857971 in words is "seven million, eight hundred fifty-seven thousand, nine hundred seventy-one".