81909035708 has 6 divisors (see below), whose sum is σ = 143340812496. Its totient is φ = 40954517852.

The previous prime is 81909035653. The next prime is 81909035737. The reversal of 81909035708 is 80753090918.

It is a super-2 number, since 2×81909035708² (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 as a sum of consecutive naturals, namely, 10238629460 + ... + 10238629467.

It is an arithmetic number, because the mean of its divisors is an integer number (23890135416).

Almost surely, 2^81909035708 is an apocalyptic number.

It is an amenable number.

81909035708 is a deficient number, since it is larger than the sum of its proper divisors (61431776788).

81909035708 is a wasteful number, since it uses less digits than its factorization.

81909035708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20477258931 (or 20477258929 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 50.

The spelling of 81909035708 in words is "eighty-one billion, nine hundred nine million, thirty-five thousand, seven hundred eight".