1721661272 has 8 divisors (see below), whose sum is σ = 3228114900. Its totient is φ = 860830632.

The previous prime is 1721661239. The next prime is 1721661373. The reversal of 1721661272 is 2721661271.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107603822 + ... + 107603837.

Almost surely, 2^1721661272 is an apocalyptic number.

It is an amenable number.

1721661272 is a deficient number, since it is larger than the sum of its proper divisors (1506453628).

1721661272 is a wasteful number, since it uses less digits than its factorization.

1721661272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215207665 (or 215207661 counting only the distinct ones).

The product of its digits is 14112, while the sum is 35.

The square root of 1721661272 is about 41492.9062852917. The cubic root of 1721661272 is about 1198.5309040500.

Subtracting 1721661272 from its reverse (2721661271), we obtain a palindrome (999999999).

The spelling of 1721661272 in words is "one billion, seven hundred twenty-one million, six hundred sixty-one thousand, two hundred seventy-two".