81779455 has 8 divisors (see below), whose sum is σ = 98208000. Its totient is φ = 65375136.

The previous prime is 81779447. The next prime is 81779459. The reversal of 81779455 is 55497718.

It is a happy number.

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 81779455 - 2³ = 81779447 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81779459) 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, 2466 + ... + 13024.

It is an arithmetic number, because the mean of its divisors is an integer number (12276000).

Almost surely, 2^81779455 is an apocalyptic number.

81779455 is a deficient number, since it is larger than the sum of its proper divisors (16428545).

81779455 is a wasteful number, since it uses less digits than its factorization.

81779455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12113.

The product of its digits is 352800, while the sum is 46.

The square root of 81779455 is about 9043.1993785385. The cubic root of 81779455 is about 434.0583055024.

The spelling of 81779455 in words is "eighty-one million, seven hundred seventy-nine thousand, four hundred fifty-five".