21031113025 has 24 divisors (see below), whose sum is σ = 28208444544. Its totient is φ = 15462196800.

The previous prime is 21031113023. The next prime is 21031113073. The reversal of 21031113025 is 52031113012.

It is not a de Polignac number, because 21031113025 - 2¹ = 21031113023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031112993 and 21031113011.

It is not an unprimeable number, because it can be changed into a prime (21031113023) 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, 68761 + ... + 216310.

It is an arithmetic number, because the mean of its divisors is an integer number (1175351856).

Almost surely, 2^21031113025 is an apocalyptic number.

21031113025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21031113025 is a deficient number, since it is larger than the sum of its proper divisors (7177331519).

21031113025 is a wasteful number, since it uses less digits than its factorization.

21031113025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285321 (or 285316 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

Adding to 21031113025 its reverse (52031113012), we get a palindrome (73062226037).

The spelling of 21031113025 in words is "twenty-one billion, thirty-one million, one hundred thirteen thousand, twenty-five".