209498197825 has 36 divisors (see below), whose sum is σ = 302290083372. Its totient is φ = 143608550400.

The previous prime is 209498197819. The next prime is 209498197847. The reversal of 209498197825 is 528791894902.

It can be written as a sum of positive squares in 6 ways, for example, as 6731710209 + 202766487616 = 82047^2 + 450296^2 .

It is not a de Polignac number, because 209498197825 - 2⁷ = 209498197697 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3914245 + ... + 3967405.

Almost surely, 2^209498197825 is an apocalyptic number.

209498197825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

209498197825 is a deficient number, since it is larger than the sum of its proper divisors (92791885547).

209498197825 is a wasteful number, since it uses less digits than its factorization.

209498197825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56402 (or 56390 counting only the distinct ones).

The product of its (nonzero) digits is 26127360, while the sum is 64.

The spelling of 209498197825 in words is "two hundred nine billion, four hundred ninety-eight million, one hundred ninety-seven thousand, eight hundred twenty-five".