81477102564 has 432 divisors, whose sum is σ = 263028205440. Its totient is φ = 21053260800.

The previous prime is 81477102559. The next prime is 81477102587. The reversal of 81477102564 is 46520177418.

81477102564 is a `hidden beast` number, since 8 + 1 + 4 + 77 + 10 + 2 + 564 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 44112289 + ... + 44114135.

Almost surely, 2^81477102564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81477102564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131514102720).

81477102564 is an abundant number, since it is smaller than the sum of its proper divisors (181551102876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81477102564 is a wasteful number, since it uses less digits than its factorization.

81477102564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1952 (or 1936 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

It can be divided in two parts, 81477 and 102564, that added together give a square (184041 = 429²).

The spelling of 81477102564 in words is "eighty-one billion, four hundred seventy-seven million, one hundred two thousand, five hundred sixty-four".