7725661 has 4 divisors (see below), whose sum is σ = 7770492. Its totient is φ = 7680832.

The previous prime is 7725659. The next prime is 7725689. The reversal of 7725661 is 1665277.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5712100 + 2013561 = 2390^2 + 1419^2 .

It is a cyclic number.

It is not a de Polignac number, because 7725661 - 2¹ = 7725659 is a prime.

It is a super-3 number, since 3×7725661³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

7725661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7725611) 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, 22156 + ... + 22501.

It is an arithmetic number, because the mean of its divisors is an integer number (1942623).

Almost surely, 2^7725661 is an apocalyptic number.

It is an amenable number.

7725661 is a deficient number, since it is larger than the sum of its proper divisors (44831).

7725661 is a wasteful number, since it uses less digits than its factorization.

7725661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44830.

The product of its digits is 17640, while the sum is 34.

The square root of 7725661 is about 2779.5073304455. The cubic root of 7725661 is about 197.6871995306.

The spelling of 7725661 in words is "seven million, seven hundred twenty-five thousand, six hundred sixty-one".