77638971 has 8 divisors (see below), whose sum is σ = 105721344. Its totient is φ = 50657960.

The previous prime is 77638969. The next prime is 77638993. The reversal of 77638971 is 17983677.

It is a happy number.

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 77638971 - 2¹ = 77638969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77638971.

It is not an unprimeable number, because it can be changed into a prime (77633971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275175 + ... + 275456.

It is an arithmetic number, because the mean of its divisors is an integer number (13215168).

Almost surely, 2^77638971 is an apocalyptic number.

77638971 is a deficient number, since it is larger than the sum of its proper divisors (28082373).

77638971 is a wasteful number, since it uses less digits than its factorization.

77638971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550681.

The product of its digits is 444528, while the sum is 48.

The square root of 77638971 is about 8811.2979180141. The cubic root of 77638971 is about 426.6056374977.

The spelling of 77638971 in words is "seventy-seven million, six hundred thirty-eight thousand, nine hundred seventy-one".