1721319912 has 96 divisors (see below), whose sum is σ = 5031772200. Its totient is φ = 528450048.

The previous prime is 1721319863. The next prime is 1721319913. The reversal of 1721319912 is 2199131271.

It can be written as a sum of positive squares in 4 ways, for example, as 836019396 + 885300516 = 28914^2 + 29754^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 (1721319913) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 474618 + ... + 478230.

Almost surely, 2^1721319912 is an apocalyptic number.

1721319912 is a gapful number since it is divisible by the number (12) 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 1721319912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2515886100).

1721319912 is an abundant number, since it is smaller than the sum of its proper divisors (3310452288).

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

1721319912 is a wasteful number, since it uses less digits than its factorization.

1721319912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4147 (or 4140 counting only the distinct ones).

The product of its digits is 6804, while the sum is 36.

The square root of 1721319912 is about 41488.7926071608. The cubic root of 1721319912 is about 1198.4516864635.

The spelling of 1721319912 in words is "one billion, seven hundred twenty-one million, three hundred nineteen thousand, nine hundred twelve".