261432140477621 has 4 divisors (see below), whose sum is σ = 261489184370592. Its totient is φ = 261375096584652.

The previous prime is 261432140477597. The next prime is 261432140477633. The reversal of 261432140477621 is 126774041234162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261432140477621 - 2¹⁰ = 261432140476597 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 261432140477621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261432140467621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28521939611 + ... + 28521948776.

It is an arithmetic number, because the mean of its divisors is an integer number (65372296092648).

Almost surely, 2^{261432140477621} is an apocalyptic number.

It is an amenable number.

261432140477621 is a deficient number, since it is larger than the sum of its proper divisors (57043892971).

261432140477621 is an equidigital number, since it uses as much as digits as its factorization.

261432140477621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57043892970.

The product of its (nonzero) digits is 2709504, while the sum is 50.

The spelling of 261432140477621 in words is "two hundred sixty-one trillion, four hundred thirty-two billion, one hundred forty million, four hundred seventy-seven thousand, six hundred twenty-one".