21661483 has 2 divisors, whose sum is σ = 21661484. Its totient is φ = 21661482.

The previous prime is 21661477. The next prime is 21661487. The reversal of 21661483 is 38416612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21661483 is a prime.

It is not a weakly prime, because it can be changed into another prime (21661487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10830741 + 10830742.

It is an arithmetic number, because the mean of its divisors is an integer number (10830742).

Almost surely, 2^21661483 is an apocalyptic number.

21661483 is a deficient number, since it is larger than the sum of its proper divisors (1).

21661483 is an equidigital number, since it uses as much as digits as its factorization.

21661483 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 31.

The square root of 21661483 is about 4654.1898328281. The cubic root of 21661483 is about 278.7593193342.

The spelling of 21661483 in words is "twenty-one million, six hundred sixty-one thousand, four hundred eighty-three".