81421979703 has 8 divisors (see below), whose sum is σ = 108565205616. Its totient is φ = 54280036800.

The previous prime is 81421979699. The next prime is 81421979713. The reversal of 81421979703 is 30797912418.

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

It is not a de Polignac number, because 81421979703 - 2² = 81421979699 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81421979713) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 161358 + ... + 434603.

It is an arithmetic number, because the mean of its divisors is an integer number (13570650702).

Almost surely, 2^81421979703 is an apocalyptic number.

81421979703 is a deficient number, since it is larger than the sum of its proper divisors (27143225913).

81421979703 is a wasteful number, since it uses less digits than its factorization.

81421979703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641505.

The product of its (nonzero) digits is 762048, while the sum is 51.

The spelling of 81421979703 in words is "eighty-one billion, four hundred twenty-one million, nine hundred seventy-nine thousand, seven hundred three".