81499069 has 8 divisors (see below), whose sum is σ = 82146168. Its totient is φ = 80855040.

The previous prime is 81499063. The next prime is 81499133. The reversal of 81499069 is 96099418.

It can be written as a sum of positive squares in 4 ways, for example, as 30946969 + 50552100 = 5563^2 + 7110^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81499069 - 2⁷ = 81498941 is a prime.

It is a super-2 number, since 2×81499069² = 13284196495733522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81499063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86139 + ... + 87079.

It is an arithmetic number, because the mean of its divisors is an integer number (10268271).

Almost surely, 2^81499069 is an apocalyptic number.

It is an amenable number.

81499069 is a deficient number, since it is larger than the sum of its proper divisors (647099).

81499069 is a wasteful number, since it uses less digits than its factorization.

81499069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1535.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 81499069 is about 9027.6834791656. The cubic root of 81499069 is about 433.5616720982.

The spelling of 81499069 in words is "eighty-one million, four hundred ninety-nine thousand, sixty-nine".