21421532 has 24 divisors (see below), whose sum is σ = 41014512. Its totient is φ = 9708800.

The previous prime is 21421489. The next prime is 21421537. The reversal of 21421532 is 23512412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25682 + ... + 26502.

It is an arithmetic number, because the mean of its divisors is an integer number (1708938).

Almost surely, 2^21421532 is an apocalyptic number.

21421532 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21421532 is a deficient number, since it is larger than the sum of its proper divisors (19592980).

21421532 is a wasteful number, since it uses less digits than its factorization.

21421532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1429 (or 1427 counting only the distinct ones).

The product of its digits is 480, while the sum is 20.

The square root of 21421532 is about 4628.3400912206. The cubic root of 21421532 is about 277.7261938465.

Adding to 21421532 its reverse (23512412), we get a palindrome (44933944).

The spelling of 21421532 in words is "twenty-one million, four hundred twenty-one thousand, five hundred thirty-two".