7809681 has 16 divisors (see below), whose sum is σ = 12028608. Its totient is φ = 4454400.

The previous prime is 7809679. The next prime is 7809689. The reversal of 7809681 is 1869087.

It is not a de Polignac number, because 7809681 - 2¹ = 7809679 is a prime.

It is a super-2 number, since 2×7809681² = 121982234643522, which contains 22 as substring.

7809681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7809689) 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, 6400 + ... + 7521.

It is an arithmetic number, because the mean of its divisors is an integer number (751788).

Almost surely, 2^7809681 is an apocalyptic number.

It is an amenable number.

7809681 is a deficient number, since it is larger than the sum of its proper divisors (4218927).

7809681 is a wasteful number, since it uses less digits than its factorization.

7809681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13952.

The product of its (nonzero) digits is 24192, while the sum is 39.

The square root of 7809681 is about 2794.5806483263. The cubic root of 7809681 is about 198.4012625792.

The spelling of 7809681 in words is "seven million, eight hundred nine thousand, six hundred eighty-one".