9959840401 has 27 divisors (see below), whose sum is σ = 11852725521. Its totient is φ = 8344793184.

The previous prime is 9959840393. The next prime is 9959840419. The reversal of 9959840401 is 1040489599.

It is a happy number.

The square root of 9959840401 is 99799.

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

It can be written as a sum of positive squares in 4 ways, for example, as 854100625 + 9105739776 = 29225^2 + 95424^2 .

It is not a de Polignac number, because 9959840401 - 2³ = 9959840393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (9959840441) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 37025295 + ... + 37025563.

Almost surely, 2^9959840401 is an apocalyptic number.

9959840401 is the 99799-th square number.

9959840401 is the 49900-th centered octagonal number.

It is an amenable number.

9959840401 is a deficient number, since it is larger than the sum of its proper divisors (1892885120).

9959840401 is an frugal number, since it uses more digits than its factorization.

9959840401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658 (or 329 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 49.

The cubic root of 9959840401 is about 2151.5467795565.

Multiplying 9959840401 by its sum of digits (49), we get a square (488032179649 = 698593²).

9959840401 divided by its sum of digits (49) gives a square (203262049 = 14257²).

The spelling of 9959840401 in words is "nine billion, nine hundred fifty-nine million, eight hundred forty thousand, four hundred one".