81020547544 has 16 divisors (see below), whose sum is σ = 151925595120. Its totient is φ = 40507055520.

The previous prime is 81020547541. The next prime is 81020547547. The reversal of 81020547544 is 44574502018.

It is an interprime number because it is at equal distance from previous prime (81020547541) and next prime (81020547547).

It is a junction number, because it is equal to n+sod(n) for n = 81020547497 and 81020547506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81020547541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 293559 + ... + 498214.

It is an arithmetic number, because the mean of its divisors is an integer number (9495349695).

Almost surely, 2^81020547544 is an apocalyptic number.

It is an amenable number.

81020547544 is a deficient number, since it is larger than the sum of its proper divisors (70905047576).

81020547544 is a wasteful number, since it uses less digits than its factorization.

81020547544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804570 (or 804566 counting only the distinct ones).

The product of its (nonzero) digits is 179200, while the sum is 40.

The spelling of 81020547544 in words is "eighty-one billion, twenty million, five hundred forty-seven thousand, five hundred forty-four".