7657681 has 4 divisors (see below), whose sum is σ = 7671664. Its totient is φ = 7643700.

The previous prime is 7657679. The next prime is 7657687. The reversal of 7657681 is 1867567.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7657681 - 2¹ = 7657679 is a prime.

It is a super-2 number, since 2×7657681² = 117280156595522, which contains 22 as substring.

It is a Duffinian number.

7657681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7657687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6135 + ... + 7276.

It is an arithmetic number, because the mean of its divisors is an integer number (1917916).

Almost surely, 2^7657681 is an apocalyptic number.

It is an amenable number.

7657681 is a deficient number, since it is larger than the sum of its proper divisors (13983).

7657681 is a wasteful number, since it uses less digits than its factorization.

7657681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13982.

The product of its digits is 70560, while the sum is 40.

The square root of 7657681 is about 2767.2515245275. The cubic root of 7657681 is about 197.1056576324.

It can be divided in two parts, 7657 and 681, that added together give a palindrome (8338).

The spelling of 7657681 in words is "seven million, six hundred fifty-seven thousand, six hundred eighty-one".