81968608590 has 32 divisors (see below), whose sum is σ = 214608721536. Its totient is φ = 19871177760.

The previous prime is 81968608583. The next prime is 81968608597. The reversal of 81968608590 is 9580686918.

It is an interprime number because it is at equal distance from previous prime (81968608583) and next prime (81968608597).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81968608597) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124194532 + ... + 124195191.

It is an arithmetic number, because the mean of its divisors is an integer number (6706522548).

Almost surely, 2^81968608590 is an apocalyptic number.

81968608590 is an abundant number, since it is smaller than the sum of its proper divisors (132640112946).

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

81968608590 is a wasteful number, since it uses less digits than its factorization.

81968608590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248389744.

The product of its (nonzero) digits is 7464960, while the sum is 60.

The spelling of 81968608590 in words is "eighty-one billion, nine hundred sixty-eight million, six hundred eight thousand, five hundred ninety".