21003357 has 8 divisors (see below), whose sum is σ = 28687680. Its totient is φ = 13660640.

The previous prime is 21003349. The next prime is 21003371. The reversal of 21003357 is 75330012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21003357 - 2³ = 21003349 is a prime.

It is a super-2 number, since 2×21003357² = 882282010538898, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003397) 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, 85257 + ... + 85502.

It is an arithmetic number, because the mean of its divisors is an integer number (3585960).

Almost surely, 2^21003357 is an apocalyptic number.

It is an amenable number.

21003357 is a deficient number, since it is larger than the sum of its proper divisors (7684323).

21003357 is a wasteful number, since it uses less digits than its factorization.

21003357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170803.

The product of its (nonzero) digits is 630, while the sum is 21.

The square root of 21003357 is about 4582.9419590477. The cubic root of 21003357 is about 275.9071179794.

Adding to 21003357 its reverse (75330012), we get a palindrome (96333369).

The spelling of 21003357 in words is "twenty-one million, three thousand, three hundred fifty-seven".