21303157 has 8 divisors (see below), whose sum is σ = 22006712. Its totient is φ = 20606400.

The previous prime is 21303143. The next prime is 21303187. The reversal of 21303157 is 75130312.

It can be written as a sum of positive squares in 4 ways, for example, as 14161 + 21288996 = 119^2 + 4614^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21303157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21303127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5107 + ... + 8287.

It is an arithmetic number, because the mean of its divisors is an integer number (2750839).

Almost surely, 2^21303157 is an apocalyptic number.

It is an amenable number.

21303157 is a deficient number, since it is larger than the sum of its proper divisors (703555).

21303157 is a wasteful number, since it uses less digits than its factorization.

21303157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3399.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 21303157 is about 4615.5343135979. The cubic root of 21303157 is about 277.2136786525.

Adding to 21303157 its reverse (75130312), we get a palindrome (96433469).

The spelling of 21303157 in words is "twenty-one million, three hundred three thousand, one hundred fifty-seven".