21201025 has 12 divisors (see below), whose sum is σ = 26651692. Its totient is φ = 16727040.

The previous prime is 21200987. The next prime is 21201031. The reversal of 21201025 is 52010212.

It can be written as a sum of positive squares in 6 ways, for example, as 734449 + 20466576 = 857^2 + 4524^2 .

It is not a de Polignac number, because 21201025 - 2⁷ = 21200897 is a prime.

It is a super-2 number, since 2×21201025² = 898966922101250, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200996 and 21201014.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3984 + ... + 7633.

Almost surely, 2^21201025 is an apocalyptic number.

21201025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21201025 is a deficient number, since it is larger than the sum of its proper divisors (5450667).

21201025 is a wasteful number, since it uses less digits than its factorization.

21201025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11700 (or 11695 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 21201025 is about 4604.4570798304. The cubic root of 21201025 is about 276.7699611073.

Adding to 21201025 its reverse (52010212), we get a palindrome (73211237).

The spelling of 21201025 in words is "twenty-one million, two hundred one thousand, twenty-five".