81029492 has 6 divisors (see below), whose sum is σ = 141801618. Its totient is φ = 40514744.

The previous prime is 81029491. The next prime is 81029513. The reversal of 81029492 is 29492018.

It can be written as a sum of positive squares in only one way, i.e., 41011216 + 40018276 = 6404^2 + 6326^2 .

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10128683 + ... + 10128690.

It is an arithmetic number, because the mean of its divisors is an integer number (23633603).

Almost surely, 2^81029492 is an apocalyptic number.

It is an amenable number.

81029492 is a deficient number, since it is larger than the sum of its proper divisors (60772126).

81029492 is a wasteful number, since it uses less digits than its factorization.

81029492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20257377 (or 20257375 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 81029492 is about 9001.6382953327. The cubic root of 81029492 is about 432.7273768491.

The spelling of 81029492 in words is "eighty-one million, twenty-nine thousand, four hundred ninety-two".