77946721 has 8 divisors (see below), whose sum is σ = 82162080. Its totient is φ = 73742688.

The previous prime is 77946719. The next prime is 77946767. The reversal of 77946721 is 12764977.

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 77946721 - 2¹ = 77946719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77943721) 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, 13890 + ... + 18676.

It is an arithmetic number, because the mean of its divisors is an integer number (10270260).

Almost surely, 2^77946721 is an apocalyptic number.

It is an amenable number.

77946721 is a deficient number, since it is larger than the sum of its proper divisors (4215359).

77946721 is a wasteful number, since it uses less digits than its factorization.

77946721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5663.

The product of its digits is 148176, while the sum is 43.

The square root of 77946721 is about 8828.7440216602. The cubic root of 77946721 is about 427.1685626855.

The spelling of 77946721 in words is "seventy-seven million, nine hundred forty-six thousand, seven hundred twenty-one".