21364061 has 2 divisors, whose sum is σ = 21364062. Its totient is φ = 21364060.

The previous prime is 21364009. The next prime is 21364073. The reversal of 21364061 is 16046312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21335161 + 28900 = 4619^2 + 170^2 .

It is a cyclic number.

It is not a de Polignac number, because 21364061 - 2⁶ = 21363997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21364001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682030 + 10682031.

It is an arithmetic number, because the mean of its divisors is an integer number (10682031).

Almost surely, 2^21364061 is an apocalyptic number.

It is an amenable number.

21364061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21364061 is an equidigital number, since it uses as much as digits as its factorization.

21364061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21364061 is about 4622.1273240792. The cubic root of 21364061 is about 277.4776044475.

The spelling of 21364061 in words is "twenty-one million, three hundred sixty-four thousand, sixty-one".