20185400825 has 24 divisors (see below), whose sum is σ = 25180680000. Its totient is φ = 16051210560.

The previous prime is 20185400821. The next prime is 20185400831. The reversal of 20185400825 is 52800458102.

It is a happy number.

It is not a de Polignac number, because 20185400825 - 2² = 20185400821 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20185400821) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9615626 + ... + 9617724.

It is an arithmetic number, because the mean of its divisors is an integer number (1049195000).

Almost surely, 2^20185400825 is an apocalyptic number.

20185400825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20185400825 is a deficient number, since it is larger than the sum of its proper divisors (4995279175).

20185400825 is a wasteful number, since it uses less digits than its factorization.

20185400825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4241 (or 4236 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 35.

Adding to 20185400825 its reverse (52800458102), we get a palindrome (72985858927).

The spelling of 20185400825 in words is "twenty billion, one hundred eighty-five million, four hundred thousand, eight hundred twenty-five".