7665492821 has 6 divisors (see below), whose sum is σ = 8917001910. Its totient is φ = 6570422376.

The previous prime is 7665492817. The next prime is 7665492827. The reversal of 7665492821 is 1282945667.

It can be written as a sum of positive squares in only one way, i.e., 4517721796 + 3147771025 = 67214^2 + 56105^2 .

It is not a de Polignac number, because 7665492821 - 2² = 7665492817 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7665492821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7665492827) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 78219266 + ... + 78219363.

It is an arithmetic number, because the mean of its divisors is an integer number (1486166985).

Almost surely, 2^7665492821 is an apocalyptic number.

It is an amenable number.

7665492821 is a deficient number, since it is larger than the sum of its proper divisors (1251509089).

7665492821 is a wasteful number, since it uses less digits than its factorization.

7665492821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156438643 (or 156438636 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 50.

The square root of 7665492821 is about 87552.8001893714. The cubic root of 7665492821 is about 1971.7265924077.

The spelling of 7665492821 in words is "seven billion, six hundred sixty-five million, four hundred ninety-two thousand, eight hundred twenty-one".