81028033251 has 16 divisors (see below), whose sum is σ = 124062061440. Its totient is φ = 46523272320.

The previous prime is 81028033237. The next prime is 81028033279. The reversal of 81028033251 is 15233082018.

It is not a de Polignac number, because 81028033251 - 2¹⁸ = 81027771107 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81028034251) 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, 64615030 + ... + 64616283.

It is an arithmetic number, because the mean of its divisors is an integer number (7753878840).

Almost surely, 2^81028033251 is an apocalyptic number.

81028033251 is a deficient number, since it is larger than the sum of its proper divisors (43034028189).

81028033251 is a wasteful number, since it uses less digits than its factorization.

81028033251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129231346.

The product of its (nonzero) digits is 11520, while the sum is 33.

The spelling of 81028033251 in words is "eighty-one billion, twenty-eight million, thirty-three thousand, two hundred fifty-one".