81308901929 has 8 divisors (see below), whose sum is σ = 85614140640. Its totient is φ = 77006245536.

The previous prime is 81308901923. The next prime is 81308902007. The reversal of 81308901929 is 92910980318.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81308901929 is a prime.

It is a super-2 number, since 2×81308901929² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81308901923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 580772 + ... + 707045.

It is an arithmetic number, because the mean of its divisors is an integer number (10701767580).

Almost surely, 2^81308901929 is an apocalyptic number.

It is an amenable number.

81308901929 is a deficient number, since it is larger than the sum of its proper divisors (4305238711).

81308901929 is a wasteful number, since it uses less digits than its factorization.

81308901929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291159.

The product of its (nonzero) digits is 279936, while the sum is 50.

The spelling of 81308901929 in words is "eighty-one billion, three hundred eight million, nine hundred one thousand, nine hundred twenty-nine".