81477750 has 32 divisors (see below), whose sum is σ = 203370336. Its totient is φ = 21727200.

The previous prime is 81477749. The next prime is 81477779. The reversal of 81477750 is 5777418.

It is a junction number, because it is equal to n+sod(n) for n = 81477699 and 81477708.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 53569 + ... + 55068.

It is an arithmetic number, because the mean of its divisors is an integer number (6355323).

Almost surely, 2^81477750 is an apocalyptic number.

81477750 is an abundant number, since it is smaller than the sum of its proper divisors (121892586).

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

81477750 is a wasteful number, since it uses less digits than its factorization.

81477750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108657 (or 108647 counting only the distinct ones).

The product of its (nonzero) digits is 54880, while the sum is 39.

The square root of 81477750 is about 9026.5026449894. The cubic root of 81477750 is about 433.5238642743.

The spelling of 81477750 in words is "eighty-one million, four hundred seventy-seven thousand, seven hundred fifty".