81523838 has 8 divisors (see below), whose sum is σ = 133402680. Its totient is φ = 37056280.

The previous prime is 81523837. The next prime is 81523853. The reversal of 81523838 is 83832518.

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

It is a super-2 number, since 2×81523838² = 13292272324500488, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81523837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1852793 + ... + 1852836.

It is an arithmetic number, because the mean of its divisors is an integer number (16675335).

Almost surely, 2^81523838 is an apocalyptic number.

81523838 is a deficient number, since it is larger than the sum of its proper divisors (51878842).

81523838 is a wasteful number, since it uses less digits than its factorization.

81523838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3705642.

The product of its digits is 46080, while the sum is 38.

The square root of 81523838 is about 9029.0552108180. The cubic root of 81523838 is about 433.6055899878.

The spelling of 81523838 in words is "eighty-one million, five hundred twenty-three thousand, eight hundred thirty-eight".