999998633790025 has 9 divisors (see below), whose sum is σ = 1239998501960743. Its totient is φ = 799998780541000.

The previous prime is 999998633789999. The next prime is 999998633790049. The reversal of 999998633790025 is 520097336899999.

The square root of 999998633790025 is 31622755.

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

It can be written as a sum of positive squares in only one way, i.e., 359999508164409 + 639999125625616 = 18973653^2 + 25298204^2 .

It is not a de Polignac number, because 999998633790025 - 2¹¹ = 999998633787977 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 154951500 + ... + 161276050.

Almost surely, 2^{999998633790025} is an apocalyptic number.

999998633790025 is the 31622755-th square number.

999998633790025 is the 15811378-th centered octagonal number.

It is an amenable number.

999998633790025 is a deficient number, since it is larger than the sum of its proper divisors (239999868170718).

999998633790025 is an frugal number, since it uses more digits than its factorization.

999998633790025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12649112 (or 6324556 counting only the distinct ones).

The product of its (nonzero) digits is 16070775840, while the sum is 88.

The spelling of 999998633790025 in words is "nine hundred ninety-nine trillion, nine hundred ninety-eight billion, six hundred thirty-three million, seven hundred ninety thousand, twenty-five".