81028864250 has 16 divisors (see below), whose sum is σ = 151686034344. Its totient is φ = 32411545600.

The previous prime is 81028864249. The next prime is 81028864271. The reversal of 81028864250 is 5246882018.

It can be written as a sum of positive squares in 4 ways, for example, as 8624279689 + 72404584561 = 92867^2 + 269081^2 .

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, 162057479 + ... + 162057978.

Almost surely, 2^81028864250 is an apocalyptic number.

81028864250 is a deficient number, since it is larger than the sum of its proper divisors (70657170094).

81028864250 is a wasteful number, since it uses less digits than its factorization.

81028864250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324115474 (or 324115464 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 44.

The spelling of 81028864250 in words is "eighty-one billion, twenty-eight million, eight hundred sixty-four thousand, two hundred fifty".