21253060 has 36 divisors (see below), whose sum is σ = 47424132. Its totient is φ = 7998976.

The previous prime is 21253033. The next prime is 21253093. The reversal of 21253060 is 6035212.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 2985984 + 18267076 = 1728^2 + 4274^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3942 + ... + 7618.

It is an arithmetic number, because the mean of its divisors is an integer number (1317337).

Almost surely, 2^21253060 is an apocalyptic number.

21253060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21253060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23712066).

21253060 is an abundant number, since it is smaller than the sum of its proper divisors (26171072).

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

21253060 is a wasteful number, since it uses less digits than its factorization.

21253060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3720 (or 3701 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21253060 is about 4610.1041202992. The cubic root of 21253060 is about 276.9962073794.

Adding to 21253060 its reverse (6035212), we get a palindrome (27288272).

It can be divided in two parts, 2125 and 3060, that multiplied together give a square (6502500 = 2550²).

The spelling of 21253060 in words is "twenty-one million, two hundred fifty-three thousand, sixty".