261771610643342 has 32 divisors (see below), whose sum is σ = 409303481657472. Its totient is φ = 125443108210464.

The previous prime is 261771610643321. The next prime is 261771610643351. The reversal of 261771610643342 is 243346016177162.

It is a super-2 number, since 2×261771610643342² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138694793 + ... + 140569515.

It is an arithmetic number, because the mean of its divisors is an integer number (12790733801796).

Almost surely, 2^{261771610643342} is an apocalyptic number.

261771610643342 is a deficient number, since it is larger than the sum of its proper divisors (147531871014130).

261771610643342 is a wasteful number, since it uses less digits than its factorization.

261771610643342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1902992.

The product of its (nonzero) digits is 6096384, while the sum is 53.

The spelling of 261771610643342 in words is "two hundred sixty-one trillion, seven hundred seventy-one billion, six hundred ten million, six hundred forty-three thousand, three hundred forty-two".