77161281 has 4 divisors (see below), whose sum is σ = 102881712. Its totient is φ = 51440852.

The previous prime is 77161241. The next prime is 77161313. The reversal of 77161281 is 18216177.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 77161281 - 2²² = 72966977 is a prime.

It is a super-2 number, since 2×77161281² = 11907726571121922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77161241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12860211 + ... + 12860216.

It is an arithmetic number, because the mean of its divisors is an integer number (25720428).

Almost surely, 2^77161281 is an apocalyptic number.

It is an amenable number.

77161281 is a deficient number, since it is larger than the sum of its proper divisors (25720431).

77161281 is a wasteful number, since it uses less digits than its factorization.

77161281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25720430.

The product of its digits is 4704, while the sum is 33.

The square root of 77161281 is about 8784.1494181281. The cubic root of 77161281 is about 425.7289101591.

The spelling of 77161281 in words is "seventy-seven million, one hundred sixty-one thousand, two hundred eighty-one".