77720238 has 12 divisors (see below), whose sum is σ = 168393888. Its totient is φ = 25906740.

The previous prime is 77720233. The next prime is 77720249. The reversal of 77720238 is 83202777.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77720231) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2158878 + ... + 2158913.

It is an arithmetic number, because the mean of its divisors is an integer number (14032824).

Almost surely, 2^77720238 is an apocalyptic number.

77720238 is an abundant number, since it is smaller than the sum of its proper divisors (90673650).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77720238 is a wasteful number, since it uses less digits than its factorization.

77720238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4317799 (or 4317796 counting only the distinct ones).

The product of its (nonzero) digits is 32928, while the sum is 36.

The square root of 77720238 is about 8815.9082345496. The cubic root of 77720238 is about 426.7544324932.

The spelling of 77720238 in words is "seventy-seven million, seven hundred twenty thousand, two hundred thirty-eight".