4249605721 has 27 divisors (see below), whose sum is σ = 4646131551. Its totient is φ = 3886307424.

The previous prime is 4249605713. The next prime is 4249605739. The reversal of 4249605721 is 1275069424.

The square root of 4249605721 is 65189.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 2412283225 + 1837322496 = 49115^2 + 42864^2 .

It is not a de Polignac number, because 4249605721 - 2³ = 4249605713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4249605751) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 58213741 + ... + 58213813.

Almost surely, 2^4249605721 is an apocalyptic number.

4249605721 is the 65189-th square number.

4249605721 is the 32595-th centered octagonal number.

It is an amenable number.

4249605721 is a deficient number, since it is larger than the sum of its proper divisors (396525830).

4249605721 is an frugal number, since it uses more digits than its factorization.

4249605721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 40.

The cubic root of 4249605721 is about 1619.7558084661.

The spelling of 4249605721 in words is "four billion, two hundred forty-nine million, six hundred five thousand, seven hundred twenty-one".