261821145013 has 8 divisors (see below), whose sum is σ = 263903986688. Its totient is φ = 259738635744.

The previous prime is 261821144993. The next prime is 261821145017. The reversal of 261821145013 is 310541128162.

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 261821145013 - 2¹⁷ = 261821013941 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261821145013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261821145017) 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, 1639870 + ... + 1792432.

It is an arithmetic number, because the mean of its divisors is an integer number (32987998336).

Almost surely, 2^261821145013 is an apocalyptic number.

It is an amenable number.

261821145013 is a deficient number, since it is larger than the sum of its proper divisors (2082841675).

261821145013 is a wasteful number, since it uses less digits than its factorization.

261821145013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166203.

The product of its (nonzero) digits is 11520, while the sum is 34.

The spelling of 261821145013 in words is "two hundred sixty-one billion, eight hundred twenty-one million, one hundred forty-five thousand, thirteen".