21051193 has 2 divisors, whose sum is σ = 21051194. Its totient is φ = 21051192.

The previous prime is 21051143. The next prime is 21051197. The reversal of 21051193 is 39115012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19686969 + 1364224 = 4437^2 + 1168^2 .

It is a cyclic number.

It is not a de Polignac number, because 21051193 - 2²¹ = 18954041 is a prime.

It is not a weakly prime, because it can be changed into another prime (21051197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525596 + 10525597.

It is an arithmetic number, because the mean of its divisors is an integer number (10525597).

Almost surely, 2^21051193 is an apocalyptic number.

It is an amenable number.

21051193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051193 is an equidigital number, since it uses as much as digits as its factorization.

21051193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 21051193 is about 4588.1579092268. The cubic root of 21051193 is about 276.1164223884.

The spelling of 21051193 in words is "twenty-one million, fifty-one thousand, one hundred ninety-three".