20515025 has 24 divisors (see below), whose sum is σ = 26617344. Its totient is φ = 15667200.

The previous prime is 20515013. The next prime is 20515051. The reversal of 20515025 is 52051502.

It is not a de Polignac number, because 20515025 - 2⁴ = 20515009 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20514988 and 20515006.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79697 + ... + 79953.

It is an arithmetic number, because the mean of its divisors is an integer number (1109056).

Almost surely, 2^20515025 is an apocalyptic number.

20515025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20515025 is a deficient number, since it is larger than the sum of its proper divisors (6102319).

20515025 is a wasteful number, since it uses less digits than its factorization.

20515025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 20515025 is about 4529.3514988351. The cubic root of 20515025 is about 273.7520311491.

Adding to 20515025 its reverse (52051502), we get a palindrome (72566527).

The spelling of 20515025 in words is "twenty million, five hundred fifteen thousand, twenty-five".