77640071 has 8 divisors (see below), whose sum is σ = 83759184. Its totient is φ = 71693440.

The previous prime is 77640067. The next prime is 77640077. The reversal of 77640071 is 17004677.

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 77640071 - 2² = 77640067 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77640077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42185 + ... + 43986.

It is an arithmetic number, because the mean of its divisors is an integer number (10469898).

Almost surely, 2^77640071 is an apocalyptic number.

77640071 is a deficient number, since it is larger than the sum of its proper divisors (6119113).

77640071 is a wasteful number, since it uses less digits than its factorization.

77640071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86241.

The product of its (nonzero) digits is 8232, while the sum is 32.

The square root of 77640071 is about 8811.3603376550. The cubic root of 77640071 is about 426.6076522246.

The spelling of 77640071 in words is "seventy-seven million, six hundred forty thousand, seventy-one".