7661945 has 16 divisors (see below), whose sum is σ = 9700560. Its totient is φ = 5800704.

The previous prime is 7661939. The next prime is 7661947. The reversal of 7661945 is 5491667.

It can be written as a sum of positive squares in 8 ways, for example, as 495616 + 7166329 = 704^2 + 2677^2 .

It is a cyclic number.

It is not a de Polignac number, because 7661945 - 2⁶ = 7661881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7661899 and 7661908.

It is not an unprimeable number, because it can be changed into a prime (7661947) 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, 7187 + ... + 8183.

It is an arithmetic number, because the mean of its divisors is an integer number (606285).

Almost surely, 2^7661945 is an apocalyptic number.

It is an amenable number.

7661945 is a deficient number, since it is larger than the sum of its proper divisors (2038615).

7661945 is a wasteful number, since it uses less digits than its factorization.

7661945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084.

The product of its digits is 45360, while the sum is 38.

The square root of 7661945 is about 2768.0218568501. The cubic root of 7661945 is about 197.1422353978.

The spelling of 7661945 in words is "seven million, six hundred sixty-one thousand, nine hundred forty-five".