77121305 has 8 divisors (see below), whose sum is σ = 93500232. Its totient is φ = 61060608.

The previous prime is 77121271. The next prime is 77121311. The reversal of 77121305 is 50312177.

It can be written as a sum of positive squares in 4 ways, for example, as 9815689 + 67305616 = 3133^2 + 8204^2 .

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 77121305 - 2⁶ = 77121241 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79022 + ... + 79991.

It is an arithmetic number, because the mean of its divisors is an integer number (11687529).

Almost surely, 2^77121305 is an apocalyptic number.

It is an amenable number.

77121305 is a deficient number, since it is larger than the sum of its proper divisors (16378927).

77121305 is a wasteful number, since it uses less digits than its factorization.

77121305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159115.

The product of its (nonzero) digits is 1470, while the sum is 26.

The square root of 77121305 is about 8781.8736611272. The cubic root of 77121305 is about 425.6553763927.

The spelling of 77121305 in words is "seventy-seven million, one hundred twenty-one thousand, three hundred five".