81029493 has 6 divisors (see below), whose sum is σ = 117042614. Its totient is φ = 54019656.

The previous prime is 81029491. The next prime is 81029513. The reversal of 81029493 is 39492018.

It can be written as a sum of positive squares in only one way, i.e., 75637809 + 5391684 = 8697^2 + 2322^2 .

It is not a de Polignac number, because 81029493 - 2¹ = 81029491 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81029491) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4501630 + ... + 4501647.

Almost surely, 2^81029493 is an apocalyptic number.

It is an amenable number.

81029493 is a deficient number, since it is larger than the sum of its proper divisors (36013121).

81029493 is a wasteful number, since it uses less digits than its factorization.

81029493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9003283 (or 9003280 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 81029493 is about 9001.6383508781. The cubic root of 81029493 is about 432.7273786292.

It can be divided in two parts, 810 and 29493, that added together give a palindrome (30303).

The spelling of 81029493 in words is "eighty-one million, twenty-nine thousand, four hundred ninety-three".