21611461 has 2 divisors, whose sum is σ = 21611462. Its totient is φ = 21611460.

The previous prime is 21611411. The next prime is 21611519. The reversal of 21611461 is 16411612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15880225 + 5731236 = 3985^2 + 2394^2 .

It is a cyclic number.

It is not a de Polignac number, because 21611461 - 2⁹ = 21610949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21611411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10805730 + 10805731.

It is an arithmetic number, because the mean of its divisors is an integer number (10805731).

Almost surely, 2^21611461 is an apocalyptic number.

It is an amenable number.

21611461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21611461 is an equidigital number, since it uses as much as digits as its factorization.

21611461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 22.

The square root of 21611461 is about 4648.8128592147. The cubic root of 21611461 is about 278.5445780200.

The spelling of 21611461 in words is "twenty-one million, six hundred eleven thousand, four hundred sixty-one".