81154801481 has 8 divisors (see below), whose sum is σ = 89759573064. Its totient is φ = 72887472000.

The previous prime is 81154801447. The next prime is 81154801487. The reversal of 81154801481 is 18410845118.

It can be written as a sum of positive squares in 4 ways, for example, as 23679054400 + 57475747081 = 153880^2 + 239741^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81154801481 - 2⁶ = 81154801417 is a prime.

It is a super-2 number, since 2×81154801481² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81154801487) 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, 84360020 + ... + 84360981.

It is an arithmetic number, because the mean of its divisors is an integer number (11219946633).

Almost surely, 2^81154801481 is an apocalyptic number.

It is an amenable number.

81154801481 is a deficient number, since it is larger than the sum of its proper divisors (8604771583).

81154801481 is a wasteful number, since it uses less digits than its factorization.

81154801481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168721051.

The product of its (nonzero) digits is 40960, while the sum is 41.

The spelling of 81154801481 in words is "eighty-one billion, one hundred fifty-four million, eight hundred one thousand, four hundred eighty-one".