21053355 has 8 divisors (see below), whose sum is σ = 33685392. Its totient is φ = 11228448.

The previous prime is 21053353. The next prime is 21053381. The reversal of 21053355 is 55335012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21053355 - 2¹ = 21053353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21053353) 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, 701764 + ... + 701793.

It is an arithmetic number, because the mean of its divisors is an integer number (4210674).

Almost surely, 2^21053355 is an apocalyptic number.

21053355 is a deficient number, since it is larger than the sum of its proper divisors (12632037).

21053355 is a wasteful number, since it uses less digits than its factorization.

21053355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1403565.

The product of its (nonzero) digits is 2250, while the sum is 24.

The square root of 21053355 is about 4588.3935097156. The cubic root of 21053355 is about 276.1258746360.

Adding to 21053355 its reverse (55335012), we get a palindrome (76388367).

It can be divided in two parts, 2105 and 3355, that added together give a triangular number (5460 = T₁₀₄).

The spelling of 21053355 in words is "twenty-one million, fifty-three thousand, three hundred fifty-five".