77861562121 has 8 divisors (see below), whose sum is σ = 89322989184. Its totient is φ = 66484721760.

The previous prime is 77861562073. The next prime is 77861562127. The reversal of 77861562121 is 12126516877.

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 77861562121 - 2¹⁵ = 77861529353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77861562127) 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, 21144700 + ... + 21148381.

It is an arithmetic number, because the mean of its divisors is an integer number (11165373648).

Almost surely, 2^77861562121 is an apocalyptic number.

It is an amenable number.

77861562121 is a deficient number, since it is larger than the sum of its proper divisors (11461427063).

77861562121 is a wasteful number, since it uses less digits than its factorization.

77861562121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42293351.

The product of its digits is 282240, while the sum is 46.

The spelling of 77861562121 in words is "seventy-seven billion, eight hundred sixty-one million, five hundred sixty-two thousand, one hundred twenty-one".