1721120551 has 8 divisors (see below), whose sum is σ = 1751115600. Its totient is φ = 1691183040.

The previous prime is 1721120543. The next prime is 1721120587. The reversal of 1721120551 is 1550211271.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1721120551 - 2³ = 1721120543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721420551) 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 7 ways as a sum of consecutive naturals, for example, 48315 + ... + 76003.

It is an arithmetic number, because the mean of its divisors is an integer number (218889450).

Almost surely, 2^1721120551 is an apocalyptic number.

1721120551 is a deficient number, since it is larger than the sum of its proper divisors (29995049).

1721120551 is a wasteful number, since it uses less digits than its factorization.

1721120551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28769.

The product of its (nonzero) digits is 700, while the sum is 25.

The square root of 1721120551 is about 41486.3899489941. The cubic root of 1721120551 is about 1198.4054169797.

The spelling of 1721120551 in words is "one billion, seven hundred twenty-one million, one hundred twenty thousand, five hundred fifty-one".