7921685 has 8 divisors (see below), whose sum is σ = 9556440. Its totient is φ = 6303744.

The previous prime is 7921679. The next prime is 7921687. The reversal of 7921685 is 5861297.

It can be written as a sum of positive squares in 4 ways, for example, as 42436 + 7879249 = 206^2 + 2807^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7921685 - 2⁶ = 7921621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7921687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3140 + ... + 5069.

It is an arithmetic number, because the mean of its divisors is an integer number (1194555).

Almost surely, 2^7921685 is an apocalyptic number.

It is an amenable number.

7921685 is a deficient number, since it is larger than the sum of its proper divisors (1634755).

7921685 is a wasteful number, since it uses less digits than its factorization.

7921685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8407.

The product of its digits is 30240, while the sum is 38.

The square root of 7921685 is about 2814.5488093121. The cubic root of 7921685 is about 199.3452337450.

The spelling of 7921685 in words is "seven million, nine hundred twenty-one thousand, six hundred eighty-five".