81083978890 has 16 divisors (see below), whose sum is σ = 146561840640. Its totient is φ = 32297885200.

The previous prime is 81083978881. The next prime is 81083978897. The reversal of 81083978890 is 9887938018.

It is a super-2 number, since 2×81083978890² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81083978897) 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, 16960786 + ... + 16965565.

It is an arithmetic number, because the mean of its divisors is an integer number (9160115040).

Almost surely, 2^81083978890 is an apocalyptic number.

81083978890 is a deficient number, since it is larger than the sum of its proper divisors (65477861750).

81083978890 is a wasteful number, since it uses less digits than its factorization.

81083978890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33926597.

The product of its (nonzero) digits is 6967296, while the sum is 61.

The spelling of 81083978890 in words is "eighty-one billion, eighty-three million, nine hundred seventy-eight thousand, eight hundred ninety".