81408384090 has 48 divisors (see below), whose sum is σ = 230903783136. Its totient is φ = 19735365600.

The previous prime is 81408384061. The next prime is 81408384131. The reversal of 81408384090 is 9048380418.

81408384090 is a `hidden beast` number, since 81 + 408 + 3 + 84 + 0 + 90 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41114356 + ... + 41116335.

It is an arithmetic number, because the mean of its divisors is an integer number (4810495482).

Almost surely, 2^81408384090 is an apocalyptic number.

81408384090 is an abundant number, since it is smaller than the sum of its proper divisors (149495399046).

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

81408384090 is a wasteful number, since it uses less digits than its factorization.

81408384090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82230715 (or 82230712 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 81408384090 in words is "eighty-one billion, four hundred eight million, three hundred eighty-four thousand, ninety".