21065701 has 2 divisors, whose sum is σ = 21065702. Its totient is φ = 21065700.

The previous prime is 21065641. The next prime is 21065711. The reversal of 21065701 is 10756012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19589476 + 1476225 = 4426^2 + 1215^2 .

It is a cyclic number.

It is not a de Polignac number, because 21065701 - 2¹⁵ = 21032933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21065711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10532850 + 10532851.

It is an arithmetic number, because the mean of its divisors is an integer number (10532851).

Almost surely, 2^21065701 is an apocalyptic number.

It is an amenable number.

21065701 is a deficient number, since it is larger than the sum of its proper divisors (1).

21065701 is an equidigital number, since it uses as much as digits as its factorization.

21065701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 21065701 is about 4589.7386635842. The cubic root of 21065701 is about 276.1798388600.

The spelling of 21065701 in words is "twenty-one million, sixty-five thousand, seven hundred one".