21153400 has 24 divisors (see below), whose sum is σ = 49182120. Its totient is φ = 8461280.

The previous prime is 21153373. The next prime is 21153409. The reversal of 21153400 is 435112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153409) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 52684 + ... + 53083.

It is an arithmetic number, because the mean of its divisors is an integer number (2049255).

Almost surely, 2^21153400 is an apocalyptic number.

21153400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21153400 is an abundant number, since it is smaller than the sum of its proper divisors (28028720).

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

21153400 is a wasteful number, since it uses less digits than its factorization.

21153400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105783 (or 105774 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21153400 is about 4599.2825527467. The cubic root of 21153400 is about 276.5625646632.

Adding to 21153400 its reverse (435112), we get a palindrome (21588512).

The spelling of 21153400 in words is "twenty-one million, one hundred fifty-three thousand, four hundred".