77777728153 has 4 divisors (see below), whose sum is σ = 78579560500. Its totient is φ = 76975895808.

The previous prime is 77777728111. The next prime is 77777728187. The reversal of 77777728153 is 35182777777.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38101868809 + 39675859344 = 195197^2 + 199188^2 .

It is a cyclic number.

It is not a de Polignac number, because 77777728153 - 2¹⁷ = 77777597081 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77777728091 and 77777728100.

It is not an unprimeable number, because it can be changed into a prime (77777728753) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400916028 + ... + 400916221.

It is an arithmetic number, because the mean of its divisors is an integer number (19644890125).

Almost surely, 2^77777728153 is an apocalyptic number.

It is an amenable number.

77777728153 is a deficient number, since it is larger than the sum of its proper divisors (801832347).

77777728153 is an equidigital number, since it uses as much as digits as its factorization.

77777728153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 801832346.

The product of its digits is 28235760, while the sum is 61.

The spelling of 77777728153 in words is "seventy-seven billion, seven hundred seventy-seven million, seven hundred twenty-eight thousand, one hundred fifty-three".