81538166292 has 48 divisors (see below), whose sum is σ = 207627635712. Its totient is φ = 24699494880.

The previous prime is 81538166263. The next prime is 81538166293. The reversal of 81538166292 is 29266183518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81538166293) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253623 + ... + 476865.

It is an arithmetic number, because the mean of its divisors is an integer number (4325575744).

Almost surely, 2^81538166292 is an apocalyptic number.

It is an amenable number.

81538166292 is an abundant number, since it is smaller than the sum of its proper divisors (126089469420).

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

81538166292 is a wasteful number, since it uses less digits than its factorization.

81538166292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226028 (or 226026 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 51.

The spelling of 81538166292 in words is "eighty-one billion, five hundred thirty-eight million, one hundred sixty-six thousand, two hundred ninety-two".