1721666741 has 4 divisors (see below), whose sum is σ = 1812280800. Its totient is φ = 1631052684.

The previous prime is 1721666731. The next prime is 1721666743. The reversal of 1721666741 is 1476661271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1721666741 is a prime.

It is a super-2 number, since 2×1721666741² = 5928272734131122162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721666743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45307001 + ... + 45307038.

It is an arithmetic number, because the mean of its divisors is an integer number (453070200).

Almost surely, 2^1721666741 is an apocalyptic number.

It is an amenable number.

1721666741 is a deficient number, since it is larger than the sum of its proper divisors (90614059).

1721666741 is an equidigital number, since it uses as much as digits as its factorization.

1721666741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90614058.

The product of its digits is 84672, while the sum is 41.

The square root of 1721666741 is about 41492.9721880706. The cubic root of 1721666741 is about 1198.5321731263.

The spelling of 1721666741 in words is "one billion, seven hundred twenty-one million, six hundred sixty-six thousand, seven hundred forty-one".