7857945 has 16 divisors (see below), whose sum is σ = 13969920. Its totient is φ = 4190832.

The previous prime is 7857943. The next prime is 7857947. The reversal of 7857945 is 5497587.

7857945 is a `hidden beast` number, since 78 + 579 + 4 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (7857943) and next prime (7857947).

It is not a de Polignac number, because 7857945 - 2¹ = 7857943 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 7857945.

It is not an unprimeable number, because it can be changed into a prime (7857943) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28969 + ... + 29238.

It is an arithmetic number, because the mean of its divisors is an integer number (873120).

Almost surely, 2^7857945 is an apocalyptic number.

It is an amenable number.

7857945 is a deficient number, since it is larger than the sum of its proper divisors (6111975).

7857945 is a wasteful number, since it uses less digits than its factorization.

7857945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58221 (or 58215 counting only the distinct ones).

The product of its digits is 352800, while the sum is 45.

The square root of 7857945 is about 2803.2026327042. The cubic root of 7857945 is about 198.8091315690.

The spelling of 7857945 in words is "seven million, eight hundred fifty-seven thousand, nine hundred forty-five".