81738291 has 8 divisors (see below), whose sum is σ = 111930064. Its totient is φ = 53019360.

The previous prime is 81738287. The next prime is 81738301. The reversal of 81738291 is 19283718.

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

It is not a de Polignac number, because 81738291 - 2² = 81738287 is a prime.

It is a super-2 number, since 2×81738291² = 13362296431201362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81738221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 368080 + ... + 368301.

It is an arithmetic number, because the mean of its divisors is an integer number (13991258).

Almost surely, 2^81738291 is an apocalyptic number.

81738291 is a deficient number, since it is larger than the sum of its proper divisors (30191773).

81738291 is a wasteful number, since it uses less digits than its factorization.

81738291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736421.

The product of its digits is 24192, while the sum is 39.

The square root of 81738291 is about 9040.9231276458. The cubic root of 81738291 is about 433.9854649793.

The spelling of 81738291 in words is "eighty-one million, seven hundred thirty-eight thousand, two hundred ninety-one".