81900313678 has 4 divisors (see below), whose sum is σ = 122850470520. Its totient is φ = 40950156838.

The previous prime is 81900313657. The next prime is 81900313699. The reversal of 81900313678 is 87631300918.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (81900313657) and next prime (81900313699).

It is a super-3 number, since 3×81900313678³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20475078418 + ... + 20475078421.

It is an arithmetic number, because the mean of its divisors is an integer number (30712617630).

Almost surely, 2^81900313678 is an apocalyptic number.

81900313678 is a deficient number, since it is larger than the sum of its proper divisors (40950156842).

81900313678 is a wasteful number, since it uses less digits than its factorization.

81900313678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40950156841.

The product of its (nonzero) digits is 217728, while the sum is 46.

The spelling of 81900313678 in words is "eighty-one billion, nine hundred million, three hundred thirteen thousand, six hundred seventy-eight".