28781523770 has 16 divisors (see below), whose sum is σ = 54854198568. Its totient is φ = 10835397120.

The previous prime is 28781523769. The next prime is 28781523791. The reversal of 28781523770 is 7732518782.

It can be written as a sum of positive squares in 4 ways, for example, as 28723809361 + 57714409 = 169481^2 + 7597^2 .

It is a super-2 number, since 2×28781523770² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84651371 + ... + 84651710.

Almost surely, 2^28781523770 is an apocalyptic number.

28781523770 is a deficient number, since it is larger than the sum of its proper divisors (26072674798).

28781523770 is a wasteful number, since it uses less digits than its factorization.

28781523770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169303105.

The product of its (nonzero) digits is 1317120, while the sum is 50.

The spelling of 28781523770 in words is "twenty-eight billion, seven hundred eighty-one million, five hundred twenty-three thousand, seven hundred seventy".