77071561 has 12 divisors (see below), whose sum is σ = 89799168. Its totient is φ = 65954952.

The previous prime is 77071541. The next prime is 77071567. The reversal of 77071561 is 16517077.

It is not a de Polignac number, because 77071561 - 2⁷ = 77071433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77071567) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52540 + ... + 53986.

It is an arithmetic number, because the mean of its divisors is an integer number (7483264).

Almost surely, 2^77071561 is an apocalyptic number.

It is an amenable number.

77071561 is a deficient number, since it is larger than the sum of its proper divisors (12727607).

77071561 is a wasteful number, since it uses less digits than its factorization.

77071561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2548 (or 2541 counting only the distinct ones).

The product of its (nonzero) digits is 10290, while the sum is 34.

The square root of 77071561 is about 8779.0410068526. The cubic root of 77071561 is about 425.5638394081.

The spelling of 77071561 in words is "seventy-seven million, seventy-one thousand, five hundred sixty-one".