28776305421 has 6 divisors (see below), whose sum is σ = 41565774510. Its totient is φ = 19184203608.

The previous prime is 28776305407. The next prime is 28776305477. The reversal of 28776305421 is 12450367782.

28776305421 is a `hidden beast` number, since 2 + 8 + 7 + 7 + 630 + 5 + 4 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 28743472521 + 32832900 = 169539^2 + 5730^2 .

It is not a de Polignac number, because 28776305421 - 2⁶ = 28776305357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28776305221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1598683626 + ... + 1598683643.

It is an arithmetic number, because the mean of its divisors is an integer number (6927629085).

Almost surely, 2^28776305421 is an apocalyptic number.

It is an amenable number.

28776305421 is a deficient number, since it is larger than the sum of its proper divisors (12789469089).

28776305421 is a wasteful number, since it uses less digits than its factorization.

28776305421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3197367275 (or 3197367272 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 28776305421 in words is "twenty-eight billion, seven hundred seventy-six million, three hundred five thousand, four hundred twenty-one".