77943621 has 16 divisors (see below), whose sum is σ = 118992384. Its totient is φ = 44456304.

The previous prime is 77943617. The next prime is 77943631. The reversal of 77943621 is 12634977.

It is not a de Polignac number, because 77943621 - 2² = 77943617 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 77943621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77943601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9166 + ... + 15488.

It is an arithmetic number, because the mean of its divisors is an integer number (7437024).

Almost surely, 2^77943621 is an apocalyptic number.

It is an amenable number.

77943621 is a deficient number, since it is larger than the sum of its proper divisors (41048763).

77943621 is a wasteful number, since it uses less digits than its factorization.

77943621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6920.

The product of its digits is 63504, while the sum is 39.

The square root of 77943621 is about 8828.5684570037. The cubic root of 77943621 is about 427.1628996716.

The spelling of 77943621 in words is "seventy-seven million, nine hundred forty-three thousand, six hundred twenty-one".