261628158016 has 63 divisors (see below), whose sum is σ = 551650799287. Its totient is φ = 123086397440.

The previous prime is 261628158013. The next prime is 261628158049. The reversal of 261628158016 is 610851826162.

The square root of 261628158016 is 511496.

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

It can be written as a sum of positive squares in 4 ways, for example, as 14913294400 + 246714863616 = 122120^2 + 496704^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261628158013) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 69561576 + ... + 69565336.

Almost surely, 2^261628158016 is an apocalyptic number.

261628158016 is the 511496-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261628158016

261628158016 is an abundant number, since it is smaller than the sum of its proper divisors (290022641271).

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

261628158016 is an frugal number, since it uses more digits than its factorization.

261628158016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7568 (or 3780 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 46.

The spelling of 261628158016 in words is "two hundred sixty-one billion, six hundred twenty-eight million, one hundred fifty-eight thousand, sixteen".