77720239 has 8 divisors (see below), whose sum is σ = 79955648. Its totient is φ = 75492000.

The previous prime is 77720233. The next prime is 77720249. The reversal of 77720239 is 93202777.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77720239 - 2³ = 77720231 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77720198 and 77720207.

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 7 ways as a sum of consecutive naturals, for example, 26389 + ... + 29185.

It is an arithmetic number, because the mean of its divisors is an integer number (9994456).

Almost surely, 2^77720239 is an apocalyptic number.

77720239 is a deficient number, since it is larger than the sum of its proper divisors (2235409).

77720239 is a wasteful number, since it uses less digits than its factorization.

77720239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3585.

The product of its (nonzero) digits is 37044, while the sum is 37.

The square root of 77720239 is about 8815.9082912653. The cubic root of 77720239 is about 426.7544343235.

The spelling of 77720239 in words is "seventy-seven million, seven hundred twenty thousand, two hundred thirty-nine".