1721665152 has 64 divisors (see below), whose sum is σ = 5081313600. Its totient is φ = 573887232.

The previous prime is 1721665147. The next prime is 1721665189. The reversal of 1721665152 is 2515661271.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×1721665152² = 5928261791222366208, which contains 22 as substring.

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

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 245628 + ... + 252539.

It is an arithmetic number, because the mean of its divisors is an integer number (79395525).

Almost surely, 2^1721665152 is an apocalyptic number.

1721665152 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1721665152 is an abundant number, since it is smaller than the sum of its proper divisors (3359648448).

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

1721665152 is an equidigital number, since it uses as much as digits as its factorization.

1721665152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498190 (or 498172 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 1721665152 is about 41492.9530402453. The cubic root of 1721665152 is about 1198.5318044007.

The spelling of 1721665152 in words is "one billion, seven hundred twenty-one million, six hundred sixty-five thousand, one hundred fifty-two".