7921665 has 16 divisors (see below), whose sum is σ = 14083200. Its totient is φ = 4224816.

The previous prime is 7921631. The next prime is 7921679. The reversal of 7921665 is 5661297.

It is not a de Polignac number, because 7921665 - 2⁹ = 7921153 is a prime.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29205 + ... + 29474.

It is an arithmetic number, because the mean of its divisors is an integer number (880200).

It is a Proth number, since it is equal to 967 ⋅ 2¹³ + 1 and 967 < 2¹³.

Almost surely, 2^7921665 is an apocalyptic number.

It is an amenable number.

7921665 is a deficient number, since it is larger than the sum of its proper divisors (6161535).

7921665 is a wasteful number, since it uses less digits than its factorization.

7921665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58693 (or 58687 counting only the distinct ones).

The product of its digits is 22680, while the sum is 36.

The square root of 7921665 is about 2814.5452563425. The cubic root of 7921665 is about 199.3450659815.

The spelling of 7921665 in words is "seven million, nine hundred twenty-one thousand, six hundred sixty-five".