261220818469 has 4 divisors (see below), whose sum is σ = 281314727596. Its totient is φ = 241126909344.

The previous prime is 261220818461. The next prime is 261220818479. The reversal of 261220818469 is 964818022162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 108310101025 + 152910717444 = 329105^2 + 391038^2 .

It is a cyclic number.

It is not a de Polignac number, because 261220818469 - 2³ = 261220818461 is a prime.

It is a super-2 number, since 2×261220818469² (a number of 24 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 (261220818461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10046954544 + ... + 10046954569.

It is an arithmetic number, because the mean of its divisors is an integer number (70328681899).

Almost surely, 2^261220818469 is an apocalyptic number.

It is an amenable number.

261220818469 is a deficient number, since it is larger than the sum of its proper divisors (20093909127).

261220818469 is a wasteful number, since it uses less digits than its factorization.

261220818469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20093909126.

The product of its (nonzero) digits is 663552, while the sum is 49.

The spelling of 261220818469 in words is "two hundred sixty-one billion, two hundred twenty million, eight hundred eighteen thousand, four hundred sixty-nine".