81493609420 has 24 divisors (see below), whose sum is σ = 172831005648. Its totient is φ = 32274696000.

The previous prime is 81493609411. The next prime is 81493609423. The reversal of 81493609420 is 2490639418.

It is not an unprimeable number, because it can be changed into a prime (81493609423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20169666 + ... + 20173705.

It is an arithmetic number, because the mean of its divisors is an integer number (7201291902).

Almost surely, 2^81493609420 is an apocalyptic number.

It is an amenable number.

81493609420 is an abundant number, since it is smaller than the sum of its proper divisors (91337396228).

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

81493609420 is a wasteful number, since it uses less digits than its factorization.

81493609420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40343481 (or 40343479 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 46.

It can be divided in two parts, 8149360 and 9420, that added together give a triangular number (8158780 = T₄₀₃₉).

The spelling of 81493609420 in words is "eighty-one billion, four hundred ninety-three million, six hundred nine thousand, four hundred twenty".