1056551571721 has 8 divisors (see below), whose sum is σ = 1112295823200. Its totient is φ = 1000820947680.

The previous prime is 1056551571707. The next prime is 1056551571731. The reversal of 1056551571721 is 1271751556501.

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

It is not a de Polignac number, because 1056551571721 - 2³⁵ = 1022191833353 is a prime.

It is a super-2 number, since 2×1056551571721² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1056551571731) 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, 3247516 + ... + 3558013.

It is an arithmetic number, because the mean of its divisors is an integer number (139036977900).

Almost surely, 2^{1056551571721} is an apocalyptic number.

It is an amenable number.

1056551571721 is a deficient number, since it is larger than the sum of its proper divisors (55744251479).

1056551571721 is an equidigital number, since it uses as much as digits as its factorization.

1056551571721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6813719.

The product of its (nonzero) digits is 367500, while the sum is 46.

The spelling of 1056551571721 in words is "one trillion, fifty-six billion, five hundred fifty-one million, five hundred seventy-one thousand, seven hundred twenty-one".