81083987478 has 24 divisors (see below), whose sum is σ = 189195971328. Its totient is φ = 24948919152.

The previous prime is 81083987431. The next prime is 81083987497. The reversal of 81083987478 is 87478938018.

81083987478 is a `hidden beast` number, since 8 + 1 + 0 + 83 + 9 + 87 + 478 = 666.

It is a super-2 number, since 2×81083987478² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 173256150 + ... + 173256617.

It is an arithmetic number, because the mean of its divisors is an integer number (7883165472).

Almost surely, 2^81083987478 is an apocalyptic number.

81083987478 is an abundant number, since it is smaller than the sum of its proper divisors (108111983850).

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

81083987478 is a wasteful number, since it uses less digits than its factorization.

81083987478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346512788 (or 346512785 counting only the distinct ones).

The product of its (nonzero) digits is 21676032, while the sum is 63.

The spelling of 81083987478 in words is "eighty-one billion, eighty-three million, nine hundred eighty-seven thousand, four hundred seventy-eight".