7617643661 has 4 divisors (see below), whose sum is σ = 7618084572. Its totient is φ = 7617202752.

The previous prime is 7617643633. The next prime is 7617643669. The reversal of 7617643661 is 1663467167.

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 5775088036 + 1842555625 = 75994^2 + 42925^2 .

It is a cyclic number.

It is not a de Polignac number, because 7617643661 - 2⁶ = 7617643597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7617643669) 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, 193436 + ... + 229461.

It is an arithmetic number, because the mean of its divisors is an integer number (1904521143).

Almost surely, 2^7617643661 is an apocalyptic number.

It is an amenable number.

7617643661 is a deficient number, since it is larger than the sum of its proper divisors (440911).

7617643661 is a wasteful number, since it uses less digits than its factorization.

7617643661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440910.

The product of its digits is 762048, while the sum is 47.

The square root of 7617643661 is about 87279.1135438485. The cubic root of 7617643661 is about 1967.6154215975.

The spelling of 7617643661 in words is "seven billion, six hundred seventeen million, six hundred forty-three thousand, six hundred sixty-one".