81351863 has 16 divisors (see below), whose sum is σ = 88929120. Its totient is φ = 74151936.

The previous prime is 81351847. The next prime is 81351883. The reversal of 81351863 is 36815318.

It is a cyclic number.

It is not a de Polignac number, because 81351863 - 2⁴ = 81351847 is a prime.

It is a super-2 number, since 2×81351863² = 13236251227141538, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81351883) 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, 67595 + ... + 68787.

It is an arithmetic number, because the mean of its divisors is an integer number (5558070).

Almost surely, 2^81351863 is an apocalyptic number.

81351863 is a deficient number, since it is larger than the sum of its proper divisors (7577257).

81351863 is a wasteful number, since it uses less digits than its factorization.

81351863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1346.

The product of its digits is 17280, while the sum is 35.

The square root of 81351863 is about 9019.5267614216. The cubic root of 81351863 is about 433.3004775220.

The spelling of 81351863 in words is "eighty-one million, three hundred fifty-one thousand, eight hundred sixty-three".