21263025 has 48 divisors (see below), whose sum is σ = 40675968. Its totient is φ = 9600000.

The previous prime is 21262999. The next prime is 21263041. The reversal of 21263025 is 52036212.

It is not a de Polignac number, because 21263025 - 2⁷ = 21262897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21262992 and 21263010.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52825 + ... + 53225.

It is an arithmetic number, because the mean of its divisors is an integer number (847416).

Almost surely, 2^21263025 is an apocalyptic number.

21263025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21263025 is a deficient number, since it is larger than the sum of its proper divisors (19412943).

21263025 is a wasteful number, since it uses less digits than its factorization.

21263025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 21263025 is about 4611.1847718347. The cubic root of 21263025 is about 277.0394926901.

Adding to 21263025 its reverse (52036212), we get a palindrome (73299237).

It can be divided in two parts, 2126 and 3025, that added together give a triangular number (5151 = T₁₀₁).

The spelling of 21263025 in words is "twenty-one million, two hundred sixty-three thousand, twenty-five".