81521448270 has 64 divisors (see below), whose sum is σ = 207215910720. Its totient is φ = 20454801408.

The previous prime is 81521448227. The next prime is 81521448271. The reversal of 81521448270 is 7284412518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81521448271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2086434 + ... + 2125146.

It is an arithmetic number, because the mean of its divisors is an integer number (3237748605).

Almost surely, 2^81521448270 is an apocalyptic number.

81521448270 is an abundant number, since it is smaller than the sum of its proper divisors (125694462450).

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

81521448270 is a wasteful number, since it uses less digits than its factorization.

81521448270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42869.

The product of its (nonzero) digits is 143360, while the sum is 42.

The spelling of 81521448270 in words is "eighty-one billion, five hundred twenty-one million, four hundred forty-eight thousand, two hundred seventy".