21352913 has 2 divisors, whose sum is σ = 21352914. Its totient is φ = 21352912.

The previous prime is 21352907. The next prime is 21352921. The reversal of 21352913 is 31925312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21270544 + 82369 = 4612^2 + 287^2 .

It is a cyclic number.

It is not a de Polignac number, because 21352913 - 2¹⁴ = 21336529 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21352963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676456 + 10676457.

It is an arithmetic number, because the mean of its divisors is an integer number (10676457).

Almost surely, 2^21352913 is an apocalyptic number.

It is an amenable number.

21352913 is a deficient number, since it is larger than the sum of its proper divisors (1).

21352913 is an equidigital number, since it uses as much as digits as its factorization.

21352913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 26.

The square root of 21352913 is about 4620.9212284998. The cubic root of 21352913 is about 277.4293324370.

The spelling of 21352913 in words is "twenty-one million, three hundred fifty-two thousand, nine hundred thirteen".