2781721398 has 8 divisors (see below), whose sum is σ = 5563442808. Its totient is φ = 927240464.

The previous prime is 2781721381. The next prime is 2781721399. The reversal of 2781721398 is 8931271872.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

2781721398 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2781721399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 231810111 + ... + 231810122.

It is an arithmetic number, because the mean of its divisors is an integer number (695430351).

Almost surely, 2^2781721398 is an apocalyptic number.

2781721398 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2781721398 is a wasteful number, since it uses less digits than its factorization.

2781721398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463620238.

The product of its digits is 338688, while the sum is 48.

The square root of 2781721398 is about 52742.0268666270. The cubic root of 2781721398 is about 1406.3860298949.

The spelling of 2781721398 in words is "two billion, seven hundred eighty-one million, seven hundred twenty-one thousand, three hundred ninety-eight".