28091771236 has 27 divisors (see below), whose sum is σ = 49540704633. Its totient is φ = 13938114960.

The previous prime is 28091771219. The next prime is 28091771237. The reversal of 28091771236 is 63217719082.

The square root of 28091771236 is 167606.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 309548836 + 27782222400 = 17594^2 + 166680^2 .

It is a super-2 number, since 2×28091771236² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28091771237) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 60673141 + ... + 60673603.

Almost surely, 2^28091771236 is an apocalyptic number.

28091771236 is the 167606-th square number.

It is an amenable number.

28091771236 is a deficient number, since it is larger than the sum of its proper divisors (21448933397).

28091771236 is an frugal number, since it uses more digits than its factorization.

28091771236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1292 (or 646 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 46.

The spelling of 28091771236 in words is "twenty-eight billion, ninety-one million, seven hundred seventy-one thousand, two hundred thirty-six".