261788981015437 has 32 divisors (see below), whose sum is σ = 273960317980800. Its totient is φ = 249983879574528.

The previous prime is 261788981015431. The next prime is 261788981015489. The reversal of 261788981015437 is 734510189887162.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 261788981015437 - 2³¹ = 261786833531789 is a prime.

It is a super-2 number, since 2×261788981015437² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261788981015431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1364546883 + ... + 1364738719.

It is an arithmetic number, because the mean of its divisors is an integer number (8561259936900).

It is a 1-persistent number, because it is pandigital, but 2⋅261788981015437 = 523577962030874 is not.

Almost surely, 2^{261788981015437} is an apocalyptic number.

It is an amenable number.

261788981015437 is a deficient number, since it is larger than the sum of its proper divisors (12171336965363).

261788981015437 is a wasteful number, since it uses less digits than its factorization.

261788981015437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196765.

The product of its (nonzero) digits is 162570240, while the sum is 70.

The spelling of 261788981015437 in words is "two hundred sixty-one trillion, seven hundred eighty-eight billion, nine hundred eighty-one million, fifteen thousand, four hundred thirty-seven".