77720013 has 64 divisors (see below), whose sum is σ = 144691200. Its totient is φ = 40201920.

The previous prime is 77720011. The next prime is 77720021. The reversal of 77720013 is 31002777.

It is not a de Polignac number, because 77720013 - 2¹ = 77720011 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77720011) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 82123 + ... + 83063.

It is an arithmetic number, because the mean of its divisors is an integer number (2260800).

Almost surely, 2^77720013 is an apocalyptic number.

It is an amenable number.

77720013 is a deficient number, since it is larger than the sum of its proper divisors (66971187).

77720013 is a wasteful number, since it uses less digits than its factorization.

77720013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999 (or 993 counting only the distinct ones).

The product of its (nonzero) digits is 2058, while the sum is 27.

The square root of 77720013 is about 8815.8954735183. The cubic root of 77720013 is about 426.7540206749.

The spelling of 77720013 in words is "seventy-seven million, seven hundred twenty thousand, thirteen".