261020843237 has 16 divisors (see below), whose sum is σ = 330763484544. Its totient is φ = 200058552000.

The previous prime is 261020843201. The next prime is 261020843243. The reversal of 261020843237 is 732348020162.

It is a cyclic number.

It is not a de Polignac number, because 261020843237 - 2¹² = 261020839141 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 261020843237.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261020843287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27781214 + ... + 27790607.

It is an arithmetic number, because the mean of its divisors is an integer number (20672717784).

Almost surely, 2^261020843237 is an apocalyptic number.

It is an amenable number.

261020843237 is a deficient number, since it is larger than the sum of its proper divisors (69742641307).

261020843237 is a wasteful number, since it uses less digits than its factorization.

261020843237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55571900.

The product of its (nonzero) digits is 96768, while the sum is 38.

Adding to 261020843237 its reverse (732348020162), we get a palindrome (993368863399).

The spelling of 261020843237 in words is "two hundred sixty-one billion, twenty million, eight hundred forty-three thousand, two hundred thirty-seven".