81690900378 has 8 divisors (see below), whose sum is σ = 163381800768. Its totient is φ = 27230300124.

The previous prime is 81690900373. The next prime is 81690900397. The reversal of 81690900378 is 87300909618.

It is a sphenic number, since it is the product of 3 distinct primes.

81690900378 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 81690900378.

It is not an unprimeable number, because it can be changed into a prime (81690900373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6807575026 + ... + 6807575037.

It is an arithmetic number, because the mean of its divisors is an integer number (20422725096).

Almost surely, 2^81690900378 is an apocalyptic number.

81690900378 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81690900378 is a wasteful number, since it uses less digits than its factorization.

81690900378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13615150068.

The product of its (nonzero) digits is 653184, while the sum is 51.

The spelling of 81690900378 in words is "eighty-one billion, six hundred ninety million, nine hundred thousand, three hundred seventy-eight".