81548538190 has 32 divisors (see below), whose sum is σ = 169641915840. Its totient is φ = 27645345024.

The previous prime is 81548538121. The next prime is 81548538223. The reversal of 81548538190 is 9183584518.

It is a super-2 number, since 2×81548538190² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6538597 + ... + 6551056.

It is an arithmetic number, because the mean of its divisors is an integer number (5301309870).

Almost surely, 2^81548538190 is an apocalyptic number.

81548538190 is an abundant number, since it is smaller than the sum of its proper divisors (88093377650).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81548538190 is a wasteful number, since it uses less digits than its factorization.

81548538190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13089756.

The product of its (nonzero) digits is 1382400, while the sum is 52.

The spelling of 81548538190 in words is "eighty-one billion, five hundred forty-eight million, five hundred thirty-eight thousand, one hundred ninety".