21481193 has 2 divisors, whose sum is σ = 21481194. Its totient is φ = 21481192.

The previous prime is 21481177. The next prime is 21481219. The reversal of 21481193 is 39118412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18550249 + 2930944 = 4307^2 + 1712^2 .

It is a cyclic number.

It is not a de Polignac number, because 21481193 - 2⁴ = 21481177 is a prime.

It is a super-2 number, since 2×21481193² = 922883305406498, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21441193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10740596 + 10740597.

It is an arithmetic number, because the mean of its divisors is an integer number (10740597).

Almost surely, 2^21481193 is an apocalyptic number.

It is an amenable number.

21481193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21481193 is an equidigital number, since it uses as much as digits as its factorization.

21481193 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 29.

The square root of 21481193 is about 4634.7807930904. The cubic root of 21481193 is about 277.9837861254.

The spelling of 21481193 in words is "twenty-one million, four hundred eighty-one thousand, one hundred ninety-three".