77840506 has 4 divisors (see below), whose sum is σ = 116760762. Its totient is φ = 38920252.

The previous prime is 77840479. The next prime is 77840513. The reversal of 77840506 is 60504877.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60504877 = 149 ⋅406073.

It can be written as a sum of positive squares in only one way, i.e., 77528025 + 312481 = 8805^2 + 559^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19460125 + ... + 19460128.

Almost surely, 2^77840506 is an apocalyptic number.

77840506 is a deficient number, since it is larger than the sum of its proper divisors (38920256).

77840506 is a wasteful number, since it uses less digits than its factorization.

77840506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38920255.

The product of its (nonzero) digits is 47040, while the sum is 37.

The square root of 77840506 is about 8822.7266760339. The cubic root of 77840506 is about 426.9744457610.

The spelling of 77840506 in words is "seventy-seven million, eight hundred forty thousand, five hundred six".