7494021721 has 2 divisors, whose sum is σ = 7494021722. Its totient is φ = 7494021720.

The previous prime is 7494021701. The next prime is 7494021751. The reversal of 7494021721 is 1271204947.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6961566096 + 532455625 = 83436^2 + 23075^2 .

It is a cyclic number.

It is not a de Polignac number, because 7494021721 - 2¹⁹ = 7493497433 is a prime.

It is not a weakly prime, because it can be changed into another prime (7494021701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3747010860 + 3747010861.

It is an arithmetic number, because the mean of its divisors is an integer number (3747010861).

Almost surely, 2^7494021721 is an apocalyptic number.

It is an amenable number.

7494021721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7494021721 is an equidigital number, since it uses as much as digits as its factorization.

7494021721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 7494021721 is about 86568.0178876703. The cubic root of 7494021721 is about 1956.9135896449.

The spelling of 7494021721 in words is "seven billion, four hundred ninety-four million, twenty-one thousand, seven hundred twenty-one".