398961509956 has 27 divisors (see below), whose sum is σ = 701115245271. Its totient is φ = 198646366464.

The previous prime is 398961509939. The next prime is 398961509957. The reversal of 398961509956 is 659905169893.

The square root of 398961509956 is 631634.

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 246224364100 + 152737145856 = 496210^2 + 390816^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398961509957) 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, 395402380 + ... + 395403388.

Almost surely, 2^398961509956 is an apocalyptic number.

398961509956 is the 631634-th square number.

It is an amenable number.

398961509956 is a deficient number, since it is larger than the sum of its proper divisors (302153735315).

398961509956 is an frugal number, since it uses more digits than its factorization.

398961509956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2648 (or 1324 counting only the distinct ones).

The product of its (nonzero) digits is 141717600, while the sum is 70.

The spelling of 398961509956 in words is "three hundred ninety-eight billion, nine hundred sixty-one million, five hundred nine thousand, nine hundred fifty-six".