21262530 has 16 divisors (see below), whose sum is σ = 51030144. Its totient is φ = 5670000.

The previous prime is 21262519. The next prime is 21262541. The reversal of 21262530 is 3526212.

It is an interprime number because it is at equal distance from previous prime (21262519) and next prime (21262541).

It is a zygodrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 21262497 and 21262506.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 354346 + ... + 354405.

It is an arithmetic number, because the mean of its divisors is an integer number (3189384).

Almost surely, 2^21262530 is an apocalyptic number.

21262530 is an abundant number, since it is smaller than the sum of its proper divisors (29767614).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21262530 is a wasteful number, since it uses less digits than its factorization.

21262530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708761.

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

The square root of 21262530 is about 4611.1310976809. The cubic root of 21262530 is about 277.0373428609.

Adding to 21262530 its reverse (3526212), we get a palindrome (24788742).

It can be divided in two parts, 2126 and 2530, that added together give a triangular number (4656 = T₉₆).

The spelling of 21262530 in words is "twenty-one million, two hundred sixty-two thousand, five hundred thirty".