1056621063661 has 4 divisors (see below), whose sum is σ = 1056625949500. Its totient is φ = 1056616177824.

The previous prime is 1056621063653. The next prime is 1056621063683. The reversal of 1056621063661 is 1663601266501.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 776282582761 + 280338480900 = 881069^2 + 529470^2 .

It is a cyclic number.

It is not a de Polignac number, because 1056621063661 - 2³ = 1056621063653 is a prime.

It is a super-2 number, since 2×1056621063661² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1056621063611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2102736 + ... + 2556313.

It is an arithmetic number, because the mean of its divisors is an integer number (264156487375).

Almost surely, 2^{1056621063661} is an apocalyptic number.

It is an amenable number.

1056621063661 is a deficient number, since it is larger than the sum of its proper divisors (4885839).

1056621063661 is an equidigital number, since it uses as much as digits as its factorization.

1056621063661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4885838.

The product of its (nonzero) digits is 233280, while the sum is 43.

The spelling of 1056621063661 in words is "one trillion, fifty-six billion, six hundred twenty-one million, sixty-three thousand, six hundred sixty-one".