9781407801 has 99 divisors (see below), whose sum is σ = 16574754063. Its totient is φ = 5767906320.

The previous prime is 9781407791. The next prime is 9781407809. The reversal of 9781407801 is 1087041879.

The square root of 9781407801 is 98901.

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

9781407801 is a `hidden beast` number, since 97 + 81 + 407 + 80 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 8752538025 + 1028869776 = 93555^2 + 32076^2 .

It is a tau number, because it is divible by the number of its divisors (99).

It is not a de Polignac number, because 9781407801 - 2⁹ = 9781407289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9781407809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 98 ways as a sum of consecutive naturals, for example, 264362355 + ... + 264362391.

Almost surely, 2^9781407801 is an apocalyptic number.

9781407801 is the 98901-st square number.

9781407801 is the 49451-st centered octagonal number.

It is an amenable number.

9781407801 is a deficient number, since it is larger than the sum of its proper divisors (6793346262).

9781407801 is an frugal number, since it uses more digits than its factorization.

9781407801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The cubic root of 9781407801 is about 2138.6208105317.

The spelling of 9781407801 in words is "nine billion, seven hundred eighty-one million, four hundred seven thousand, eight hundred one".