261715890443 has 16 divisors (see below), whose sum is σ = 317089805760. Its totient is φ = 210871090176.

The previous prime is 261715890427. The next prime is 261715890493. The reversal of 261715890443 is 344098517162.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 261715890443 - 2⁴ = 261715890427 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261715890391 and 261715890400.

It is not an unprimeable number, because it can be changed into a prime (261715890493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1262996 + ... + 1455537.

It is an arithmetic number, because the mean of its divisors is an integer number (19818112860).

It is a 1-persistent number, because it is pandigital, but 2⋅261715890443 = 523431780886 is not.

Almost surely, 2^261715890443 is an apocalyptic number.

261715890443 is a deficient number, since it is larger than the sum of its proper divisors (55373915317).

261715890443 is a wasteful number, since it uses less digits than its factorization.

261715890443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2719366.

The product of its (nonzero) digits is 1451520, while the sum is 50.

The spelling of 261715890443 in words is "two hundred sixty-one billion, seven hundred fifteen million, eight hundred ninety thousand, four hundred forty-three".