21132306 has 32 divisors (see below), whose sum is σ = 50574720. Its totient is φ = 6502032.

The previous prime is 21132301. The next prime is 21132311. The reversal of 21132306 is 60323112.

It is an interprime number because it is at equal distance from previous prime (21132301) and next prime (21132311).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21132301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14350 + ... + 15753.

It is an arithmetic number, because the mean of its divisors is an integer number (1580460).

Almost surely, 2^21132306 is an apocalyptic number.

21132306 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21132306 is an abundant number, since it is smaller than the sum of its proper divisors (29442414).

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

21132306 is a wasteful number, since it uses less digits than its factorization.

21132306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30127 (or 30121 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 21132306 is about 4596.9887970279. The cubic root of 21132306 is about 276.4706054359.

Adding to 21132306 its reverse (60323112), we get a palindrome (81455418).

The spelling of 21132306 in words is "twenty-one million, one hundred thirty-two thousand, three hundred six".