1721240780 has 72 divisors (see below), whose sum is σ = 4359968928. Its totient is φ = 559063296.

The previous prime is 1721240767. The next prime is 1721240789. The reversal of 1721240780 is 870421271.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1721240789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33512 + ... + 67568.

It is an arithmetic number, because the mean of its divisors is an integer number (60555124).

Almost surely, 2^1721240780 is an apocalyptic number.

1721240780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1721240780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2179984464).

1721240780 is an abundant number, since it is smaller than the sum of its proper divisors (2638728148).

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

1721240780 is a wasteful number, since it uses less digits than its factorization.

1721240780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34111 (or 34090 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 32.

The square root of 1721240780 is about 41487.8389410680. The cubic root of 1721240780 is about 1198.4333212289.

The spelling of 1721240780 in words is "one billion, seven hundred twenty-one million, two hundred forty thousand, seven hundred eighty".