21134749 has 2 divisors, whose sum is σ = 21134750. Its totient is φ = 21134748.

The previous prime is 21134717. The next prime is 21134753. The reversal of 21134749 is 94743112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15350724 + 5784025 = 3918^2 + 2405^2 .

It is a cyclic number.

It is not a de Polignac number, because 21134749 - 2⁵ = 21134717 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21134749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21134249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10567374 + 10567375.

It is an arithmetic number, because the mean of its divisors is an integer number (10567375).

Almost surely, 2^21134749 is an apocalyptic number.

It is an amenable number.

21134749 is a deficient number, since it is larger than the sum of its proper divisors (1).

21134749 is an equidigital number, since it uses as much as digits as its factorization.

21134749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 21134749 is about 4597.2545067681. The cubic root of 21134749 is about 276.4812588191.

The spelling of 21134749 in words is "twenty-one million, one hundred thirty-four thousand, seven hundred forty-nine".