81401761 has 8 divisors (see below), whose sum is σ = 97075584. Its totient is φ = 66739200.

The previous prime is 81401759. The next prime is 81401777. The reversal of 81401761 is 16710418.

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 81401761 - 2¹ = 81401759 is a prime.

It is a super-2 number, since 2×81401761² = 13252493387802242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81401741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 252640 + ... + 252961.

It is an arithmetic number, because the mean of its divisors is an integer number (12134448).

Almost surely, 2^81401761 is an apocalyptic number.

It is an amenable number.

81401761 is a deficient number, since it is larger than the sum of its proper divisors (15673823).

81401761 is a wasteful number, since it uses less digits than its factorization.

81401761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505631.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 81401761 is about 9022.2924470447. The cubic root of 81401761 is about 433.3890491805.

The spelling of 81401761 in words is "eighty-one million, four hundred one thousand, seven hundred sixty-one".