81250000001 has 4 divisors (see below), whose sum is σ = 81589958400. Its totient is φ = 80910041604.

The previous prime is 81249999977. The next prime is 81250000199. The reversal of 81250000001 is 10000005218.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81250000001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81250000301) 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, 169978841 + ... + 169979318.

It is an arithmetic number, because the mean of its divisors is an integer number (20397489600).

Almost surely, 2^81250000001 is an apocalyptic number.

It is an amenable number.

81250000001 is a deficient number, since it is larger than the sum of its proper divisors (339958399).

81250000001 is a wasteful number, since it uses less digits than its factorization.

81250000001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339958398.

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 81250000001 its reverse (10000005218), we get a palindrome (91250005219).

The spelling of 81250000001 in words is "eighty-one billion, two hundred fifty million, one", and thus it is an aban number.