81054659401 has 3 divisors (see below), whose sum is σ = 81054944103. Its totient is φ = 81054374700.

The previous prime is 81054659393. The next prime is 81054659417. The reversal of 81054659401 is 10495645018.

The square root of 81054659401 is 284701.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 10495645018 = 2 ⋅5247822509.

It can be written as a sum of positive squares in only one way, i.e., 27109951801 + 53944707600 = 164651^2 + 232260^2 .

It is not a de Polignac number, because 81054659401 - 2³ = 81054659393 is a prime.

It is a super-2 number, since 2×81054659401² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81055659401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 142351 + ... + 427051.

It is an arithmetic number, because the mean of its divisors is an integer number (27018314701).

Almost surely, 2^81054659401 is an apocalyptic number.

81054659401 is the 284701-st square number.

81054659401 is the 142351-st centered octagonal number.

It is an amenable number.

81054659401 is a deficient number, since it is larger than the sum of its proper divisors (284702).

81054659401 is an frugal number, since it uses more digits than its factorization.

81054659401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 569402 (or 284701 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 43.

The spelling of 81054659401 in words is "eighty-one billion, fifty-four million, six hundred fifty-nine thousand, four hundred one".