81259838 has 16 divisors (see below), whose sum is σ = 133384320. Its totient is φ = 36821400.

The previous prime is 81259831. The next prime is 81259879. The reversal of 81259838 is 83895218.

It is a super-2 number, since 2×81259838² = 13206322543572488, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81259831) 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, 1703 + ... + 12861.

It is an arithmetic number, because the mean of its divisors is an integer number (8336520).

Almost surely, 2^81259838 is an apocalyptic number.

81259838 is a deficient number, since it is larger than the sum of its proper divisors (52124482).

81259838 is a wasteful number, since it uses less digits than its factorization.

81259838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11503.

The product of its digits is 138240, while the sum is 44.

The square root of 81259838 is about 9014.4238861948. The cubic root of 81259838 is about 433.1370331143.

The spelling of 81259838 in words is "eighty-one million, two hundred fifty-nine thousand, eight hundred thirty-eight".