656212551121 has 8 divisors (see below), whose sum is σ = 656711455400. Its totient is φ = 655713781632.

The previous prime is 656212551119. The next prime is 656212551139. The reversal of 656212551121 is 121155212656.

It can be written as a sum of positive squares in 4 ways, for example, as 210556170496 + 445656380625 = 458864^2 + 667575^2 .

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 656212551121 - 2¹ = 656212551119 is a prime.

It is a super-2 number, since 2×656212551121² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656212551161) 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, 11064655 + ... + 11123803.

It is an arithmetic number, because the mean of its divisors is an integer number (82088931925).

Almost surely, 2^656212551121 is an apocalyptic number.

It is an amenable number.

656212551121 is a deficient number, since it is larger than the sum of its proper divisors (498904279).

656212551121 is a wasteful number, since it uses less digits than its factorization.

656212551121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67395.

The product of its digits is 36000, while the sum is 37.

Adding to 656212551121 its reverse (121155212656), we get a palindrome (777367763777).

The spelling of 656212551121 in words is "six hundred fifty-six billion, two hundred twelve million, five hundred fifty-one thousand, one hundred twenty-one".