728122091986 has 8 divisors (see below), whose sum is σ = 1092186802044. Its totient is φ = 364059824640.

The previous prime is 728122091971. The next prime is 728122092023. The reversal of 728122091986 is 689190221827.

It can be written as a sum of positive squares in 2 ways, for example, as 699790806225 + 28331285761 = 836535^2 + 168319^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 680626 + ... + 1385458.

Almost surely, 2^728122091986 is an apocalyptic number.

728122091986 is a deficient number, since it is larger than the sum of its proper divisors (364064710058).

728122091986 is a wasteful number, since it uses less digits than its factorization.

728122091986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1221356.

The product of its (nonzero) digits is 1741824, while the sum is 55.

The spelling of 728122091986 in words is "seven hundred twenty-eight billion, one hundred twenty-two million, ninety-one thousand, nine hundred eighty-six".