557701721 has 8 divisors (see below), whose sum is σ = 572075784. Its totient is φ = 543364480.

The previous prime is 557701717. The next prime is 557701741. The reversal of 557701721 is 127107755.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 113124496 + 444577225 = 10636^2 + 21085^2 .

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 557701721 - 2² = 557701717 is a prime.

It is a super-2 number, since 2×557701721² = 622062419212723682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (557701741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22895 + ... + 40491.

It is an arithmetic number, because the mean of its divisors is an integer number (71509473).

Almost surely, 2^557701721 is an apocalyptic number.

It is an amenable number.

557701721 is a deficient number, since it is larger than the sum of its proper divisors (14374063).

557701721 is a wasteful number, since it uses less digits than its factorization.

557701721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18411.

The product of its (nonzero) digits is 17150, while the sum is 35.

The square root of 557701721 is about 23615.7091995985. The cubic root of 557701721 is about 823.1279110555.

The spelling of 557701721 in words is "five hundred fifty-seven million, seven hundred one thousand, seven hundred twenty-one".