21088061 has 2 divisors, whose sum is σ = 21088062. Its totient is φ = 21088060.

The previous prime is 21088057. The next prime is 21088069. The reversal of 21088061 is 16088012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16048036 + 5040025 = 4006^2 + 2245^2 .

It is a cyclic number.

It is not a de Polignac number, because 21088061 - 2² = 21088057 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21088061.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21088069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10544030 + 10544031.

It is an arithmetic number, because the mean of its divisors is an integer number (10544031).

Almost surely, 2^21088061 is an apocalyptic number.

It is an amenable number.

21088061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21088061 is an equidigital number, since it uses as much as digits as its factorization.

21088061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 21088061 is about 4592.1738860805. The cubic root of 21088061 is about 276.2775205140.

The spelling of 21088061 in words is "twenty-one million, eighty-eight thousand, sixty-one".