81356523490 has 32 divisors (see below), whose sum is σ = 162139040064. Its totient is φ = 29142632640.

The previous prime is 81356523481. The next prime is 81356523511. The reversal of 81356523490 is 9432565318.

It is a self number, because there is not a number n which added to its sum of digits gives 81356523490.

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, 5512069 + ... + 5526808.

It is an arithmetic number, because the mean of its divisors is an integer number (5066845002).

Almost surely, 2^81356523490 is an apocalyptic number.

81356523490 is a deficient number, since it is larger than the sum of its proper divisors (80782516574).

81356523490 is a wasteful number, since it uses less digits than its factorization.

81356523490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11038962.

The product of its (nonzero) digits is 777600, while the sum is 46.

The spelling of 81356523490 in words is "eighty-one billion, three hundred fifty-six million, five hundred twenty-three thousand, four hundred ninety".