1721047680 has 384 divisors, whose sum is σ = 6770874240. Its totient is φ = 398745600.

The previous prime is 1721047673. The next prime is 1721047681. The reversal of 1721047680 is 867401271.

1721047680 is a `hidden beast` number, since 172 + 10 + 476 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1721047681) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1456690 + ... + 1457870.

It is an arithmetic number, because the mean of its divisors is an integer number (17632485).

Almost surely, 2^1721047680 is an apocalyptic number.

1721047680 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 1721047680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3385437120).

1721047680 is an abundant number, since it is smaller than the sum of its proper divisors (5049826560).

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

1721047680 is a wasteful number, since it uses less digits than its factorization.

1721047680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1240 (or 1225 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 1721047680 is about 41485.5116878170. The cubic root of 1721047680 is about 1198.3885035347.

The spelling of 1721047680 in words is "one billion, seven hundred twenty-one million, forty-seven thousand, six hundred eighty".