261722161061 has 8 divisors (see below), whose sum is σ = 263662224000. Its totient is φ = 259788347280.

The previous prime is 261722161049. The next prime is 261722161069. The reversal of 261722161061 is 160161227162.

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 261722161061 - 2¹⁸ = 261721898917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261722161069) 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, 1478201 + ... + 1645758.

It is an arithmetic number, because the mean of its divisors is an integer number (32957778000).

Almost surely, 2^261722161061 is an apocalyptic number.

It is an amenable number.

261722161061 is a deficient number, since it is larger than the sum of its proper divisors (1940062939).

261722161061 is a wasteful number, since it uses less digits than its factorization.

261722161061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3124579.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 261722161061 in words is "two hundred sixty-one billion, seven hundred twenty-two million, one hundred sixty-one thousand, sixty-one".