81277448464 has 45 divisors (see below), whose sum is σ = 158661556599. Its totient is φ = 40334816160.

The previous prime is 81277448453. The next prime is 81277448467. The reversal of 81277448464 is 46484477218.

It is a happy number.

The square root of 81277448464 is 285092.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81277448467) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 299916649 + ... + 299916919.

Almost surely, 2^81277448464 is an apocalyptic number.

81277448464 is the 285092-nd square number.

It is an amenable number.

81277448464 is a deficient number, since it is larger than the sum of its proper divisors (77384108135).

81277448464 is an frugal number, since it uses more digits than its factorization.

81277448464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1076 (or 536 counting only the distinct ones).

The product of its digits is 9633792, while the sum is 55.

The spelling of 81277448464 in words is "eighty-one billion, two hundred seventy-seven million, four hundred forty-eight thousand, four hundred sixty-four".