28781771086 has 32 divisors (see below), whose sum is σ = 45878337792. Its totient is φ = 13495251840.

The previous prime is 28781771071. The next prime is 28781771089. The reversal of 28781771086 is 68017718782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28781771089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13789935 + ... + 13792021.

It is an arithmetic number, because the mean of its divisors is an integer number (1433698056).

Almost surely, 2^28781771086 is an apocalyptic number.

28781771086 is a deficient number, since it is larger than the sum of its proper divisors (17096566706).

28781771086 is a wasteful number, since it uses less digits than its factorization.

28781771086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3384.

The product of its (nonzero) digits is 2107392, while the sum is 55.

The spelling of 28781771086 in words is "twenty-eight billion, seven hundred eighty-one million, seven hundred seventy-one thousand, eighty-six".