7891645 has 16 divisors (see below), whose sum is σ = 9965952. Its totient is φ = 5987520.

The previous prime is 7891613. The next prime is 7891649. The reversal of 7891645 is 5461987.

It is not a de Polignac number, because 7891645 - 2⁵ = 7891613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7891598 and 7891607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7891649) 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, 18535 + ... + 18955.

It is an arithmetic number, because the mean of its divisors is an integer number (622872).

Almost surely, 2^7891645 is an apocalyptic number.

It is an amenable number.

7891645 is a deficient number, since it is larger than the sum of its proper divisors (2074307).

7891645 is a wasteful number, since it uses less digits than its factorization.

7891645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612.

The product of its digits is 60480, while the sum is 40.

The square root of 7891645 is about 2809.2071835306. The cubic root of 7891645 is about 199.0929340426.

It can be divided in two parts, 78916 and 45, that added together give a square (78961 = 281²).

The spelling of 7891645 in words is "seven million, eight hundred ninety-one thousand, six hundred forty-five".