81424051801 has 9 divisors (see below), whose sum is σ = 82607576053. Its totient is φ = 80257259740.

The previous prime is 81424051777. The next prime is 81424051867. The reversal of 81424051801 is 10815042418.

It is a happy number.

The square root of 81424051801 is 285349.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 81424051801 - 2⁷ = 81424051673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81424051901) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 20257770 + ... + 20261788.

Almost surely, 2^81424051801 is an apocalyptic number.

81424051801 is the 285349-th square number.

81424051801 is the 142675-th centered octagonal number.

It is an amenable number.

81424051801 is a deficient number, since it is larger than the sum of its proper divisors (1183524252).

81424051801 is an frugal number, since it uses more digits than its factorization.

81424051801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8180 (or 4090 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 34.

The spelling of 81424051801 in words is "eighty-one billion, four hundred twenty-four million, fifty-one thousand, eight hundred one".