21186701 has 2 divisors, whose sum is σ = 21186702. Its totient is φ = 21186700.

The previous prime is 21186677. The next prime is 21186769. The reversal of 21186701 is 10768112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20921476 + 265225 = 4574^2 + 515^2 .

It is a cyclic number.

It is not a de Polignac number, because 21186701 - 2⁶ = 21186637 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21188701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10593350 + 10593351.

It is an arithmetic number, because the mean of its divisors is an integer number (10593351).

Almost surely, 2^21186701 is an apocalyptic number.

It is an amenable number.

21186701 is a deficient number, since it is larger than the sum of its proper divisors (1).

21186701 is an equidigital number, since it uses as much as digits as its factorization.

21186701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 21186701 is about 4602.9013676159. The cubic root of 21186701 is about 276.7076159127.

The spelling of 21186701 in words is "twenty-one million, one hundred eighty-six thousand, seven hundred one".