81920001 has 8 divisors (see below), whose sum is σ = 114975520. Its totient is φ = 51738912.

The previous prime is 81919993. The next prime is 81920021. The reversal of 81920001 is 10002918.

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

It is not a de Polignac number, because 81920001 - 2³ = 81919993 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81920001.

It is not an unprimeable number, because it can be changed into a prime (81920021) 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, 718540 + ... + 718653.

It is an arithmetic number, because the mean of its divisors is an integer number (14371940).

It is a Proth number, since it is equal to 625 ⋅ 2¹⁷ + 1 and 625 < 2¹⁷.

Almost surely, 2^81920001 is an apocalyptic number.

It is an amenable number.

81920001 is a deficient number, since it is larger than the sum of its proper divisors (33055519).

81920001 is a wasteful number, since it uses less digits than its factorization.

81920001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1437215.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 81920001 is about 9050.9668544305. The cubic root of 81920001 is about 434.3068204224.

Adding to 81920001 its reverse (10002918), we get a palindrome (91922919).

The spelling of 81920001 in words is "eighty-one million, nine hundred twenty thousand, one".