76720561 has 8 divisors (see below), whose sum is σ = 78037344. Its totient is φ = 75408960.

The previous prime is 76720531. The next prime is 76720577. The reversal of 76720561 is 16502767.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 76720561 - 2⁵ = 76720529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76720531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38766 + ... + 40696.

It is an arithmetic number, because the mean of its divisors is an integer number (9754668).

Almost surely, 2^76720561 is an apocalyptic number.

It is an amenable number.

76720561 is a deficient number, since it is larger than the sum of its proper divisors (1316783).

76720561 is a wasteful number, since it uses less digits than its factorization.

76720561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2591.

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

The square root of 76720561 is about 8759.0274003453. The cubic root of 76720561 is about 424.9168206304.

The spelling of 76720561 in words is "seventy-six million, seven hundred twenty thousand, five hundred sixty-one".