21013357 has 2 divisors, whose sum is σ = 21013358. Its totient is φ = 21013356.

The previous prime is 21013303. The next prime is 21013379. The reversal of 21013357 is 75331012.

It is an a-pointer prime, because the next prime (21013379) can be obtained adding 21013357 to its sum of digits (22).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20331081 + 682276 = 4509^2 + 826^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013357 - 2²³ = 12624749 is a prime.

It is a super-2 number, since 2×21013357² = 883122344818898, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013397) 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 as a sum of consecutive naturals, namely, 10506678 + 10506679.

It is an arithmetic number, because the mean of its divisors is an integer number (10506679).

Almost surely, 2^21013357 is an apocalyptic number.

It is an amenable number.

21013357 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013357 is an equidigital number, since it uses as much as digits as its factorization.

21013357 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21013357 is about 4584.0328314706. The cubic root of 21013357 is about 275.9508988127.

Adding to 21013357 its reverse (75331012), we get a palindrome (96344369).

The spelling of 21013357 in words is "twenty-one million, thirteen thousand, three hundred fifty-seven".