77840145 has 24 divisors (see below), whose sum is σ = 135196776. Its totient is φ = 41430528.

The previous prime is 77840141. The next prime is 77840167. The reversal of 77840145 is 54104877.

It can be written as a sum of positive squares in 4 ways, for example, as 36469521 + 41370624 = 6039^2 + 6432^2 .

It is not a de Polignac number, because 77840145 - 2² = 77840141 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77840141) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25227 + ... + 28143.

It is an arithmetic number, because the mean of its divisors is an integer number (5633199).

Almost surely, 2^77840145 is an apocalyptic number.

It is an amenable number.

77840145 is a deficient number, since it is larger than the sum of its proper divisors (57356631).

77840145 is a wasteful number, since it uses less digits than its factorization.

77840145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3521 (or 3518 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 36.

The square root of 77840145 is about 8822.7062174823. The cubic root of 77840145 is about 426.9737857019.

The spelling of 77840145 in words is "seventy-seven million, eight hundred forty thousand, one hundred forty-five".