81211463590 has 24 divisors (see below), whose sum is σ = 148045623840. Its totient is φ = 32070224784.

The previous prime is 81211463491. The next prime is 81211463611. The reversal of 81211463590 is 9536411218.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8004741 + ... + 8014879.

It is an arithmetic number, because the mean of its divisors is an integer number (6168567660).

Almost surely, 2^81211463590 is an apocalyptic number.

81211463590 is a deficient number, since it is larger than the sum of its proper divisors (66834160250).

81211463590 is an frugal number, since it uses more digits than its factorization.

81211463590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20364 (or 10225 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 40.

The spelling of 81211463590 in words is "eighty-one billion, two hundred eleven million, four hundred sixty-three thousand, five hundred ninety".