261543072657492 has 120 divisors (see below), whose sum is σ = 706041321334272. Its totient is φ = 84337603444800.

The previous prime is 261543072657481. The next prime is 261543072657499. The reversal of 261543072657492 is 294756270345162.

261543072657492 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 4 + 30 + 7 + 26 + 574 + 9 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261543072657499) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 22426678 + ... + 32031890.

Almost surely, 2^{261543072657492} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261543072657492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (353020660667136).

261543072657492 is an abundant number, since it is smaller than the sum of its proper divisors (444498248676780).

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

261543072657492 is a wasteful number, since it uses less digits than its factorization.

261543072657492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9607971 (or 9607960 counting only the distinct ones).

The product of its (nonzero) digits is 152409600, while the sum is 63.

The spelling of 261543072657492 in words is "two hundred sixty-one trillion, five hundred forty-three billion, seventy-two million, six hundred fifty-seven thousand, four hundred ninety-two".