81890125258 has 8 divisors (see below), whose sum is σ = 122836409028. Its totient is φ = 40944655584.

The previous prime is 81890125243. The next prime is 81890125279. The reversal of 81890125258 is 85252109818.

It can be written as a sum of positive squares in 2 ways, for example, as 81805724289 + 84400969 = 286017^2 + 9187^2 .

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

It is a super-2 number, since 2×81890125258² (a number of 23 digits) contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 250710 + ... + 476062.

Almost surely, 2^81890125258 is an apocalyptic number.

81890125258 is a deficient number, since it is larger than the sum of its proper divisors (40946283770).

81890125258 is a wasteful number, since it uses less digits than its factorization.

81890125258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407048.

The product of its (nonzero) digits is 460800, while the sum is 49.

The spelling of 81890125258 in words is "eighty-one billion, eight hundred ninety million, one hundred twenty-five thousand, two hundred fifty-eight".