81538797 has 8 divisors (see below), whose sum is σ = 108766944. Its totient is φ = 54334928.

The previous prime is 81538789. The next prime is 81538801. The reversal of 81538797 is 79783518.

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 81538797 - 2³ = 81538789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81538777) 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, 4303 + ... + 13475.

It is an arithmetic number, because the mean of its divisors is an integer number (13595868).

Almost surely, 2^81538797 is an apocalyptic number.

It is an amenable number.

81538797 is a deficient number, since it is larger than the sum of its proper divisors (27228147).

81538797 is a wasteful number, since it uses less digits than its factorization.

81538797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12139.

The product of its digits is 423360, while the sum is 48.

The square root of 81538797 is about 9029.8835540665. The cubic root of 81538797 is about 433.6321094676.

The spelling of 81538797 in words is "eighty-one million, five hundred thirty-eight thousand, seven hundred ninety-seven".