21357701 has 2 divisors, whose sum is σ = 21357702. Its totient is φ = 21357700.

The previous prime is 21357697. The next prime is 21357703. The reversal of 21357701 is 10775312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15602500 + 5755201 = 3950^2 + 2399^2 .

It is a cyclic number.

It is not a de Polignac number, because 21357701 - 2² = 21357697 is a prime.

Together with 21357703, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21357703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678850 + 10678851.

It is an arithmetic number, because the mean of its divisors is an integer number (10678851).

Almost surely, 2^21357701 is an apocalyptic number.

It is an amenable number.

21357701 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357701 is an equidigital number, since it uses as much as digits as its factorization.

21357701 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1470, while the sum is 26.

The square root of 21357701 is about 4621.4392779739. The cubic root of 21357701 is about 277.4500670376.

The spelling of 21357701 in words is "twenty-one million, three hundred fifty-seven thousand, seven hundred one".