509961661456 has 135 divisors (see below), whose sum is σ = 1108028513277. Its totient is φ = 227260275840.

The previous prime is 509961661387. The next prime is 509961661507. The reversal of 509961661456 is 654166169905.

The square root of 509961661456 is 714116.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 75438115600 + 434523545856 = 274660^2 + 659184^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 509961661456.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1151154771 + ... + 1151155213.

Almost surely, 2^509961661456 is an apocalyptic number.

509961661456 is the 714116-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 509961661456

509961661456 is an abundant number, since it is smaller than the sum of its proper divisors (598066851821).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

509961661456 is an equidigital number, since it uses as much as digits as its factorization.

509961661456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 982 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 10497600, while the sum is 58.

The spelling of 509961661456 in words is "five hundred nine billion, nine hundred sixty-one million, six hundred sixty-one thousand, four hundred fifty-six".