2439198721 has 4 divisors (see below), whose sum is σ = 2443178452. Its totient is φ = 2435218992.

The previous prime is 2439198659. The next prime is 2439198731. The reversal of 2439198721 is 1278919342.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1003622400 + 1435576321 = 31680^2 + 37889^2 .

It is a cyclic number.

It is not a de Polignac number, because 2439198721 - 2¹³ = 2439190529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2439198731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1988946 + ... + 1990171.

It is an arithmetic number, because the mean of its divisors is an integer number (610794613).

Almost surely, 2^2439198721 is an apocalyptic number.

It is an amenable number.

2439198721 is a deficient number, since it is larger than the sum of its proper divisors (3979731).

2439198721 is an equidigital number, since it uses as much as digits as its factorization.

2439198721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3979730.

The product of its digits is 217728, while the sum is 46.

The square root of 2439198721 is about 49388.2447653285. The cubic root of 2439198721 is about 1346.1157155112.

The spelling of 2439198721 in words is "two billion, four hundred thirty-nine million, one hundred ninety-eight thousand, seven hundred twenty-one".