21149393 has 2 divisors, whose sum is σ = 21149394. Its totient is φ = 21149392.

The previous prime is 21149383. The next prime is 21149407. The reversal of 21149393 is 39394112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19775809 + 1373584 = 4447^2 + 1172^2 .

It is a cyclic number.

It is not a de Polignac number, because 21149393 - 2¹⁴ = 21133009 is a prime.

It is not a weakly prime, because it can be changed into another prime (21149333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10574696 + 10574697.

It is an arithmetic number, because the mean of its divisors is an integer number (10574697).

Almost surely, 2^21149393 is an apocalyptic number.

It is an amenable number.

21149393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21149393 is an equidigital number, since it uses as much as digits as its factorization.

21149393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 32.

The square root of 21149393 is about 4598.8469206965. The cubic root of 21149393 is about 276.5451008642.

The spelling of 21149393 in words is "twenty-one million, one hundred forty-nine thousand, three hundred ninety-three".