261432140477566 has 4 divisors (see below), whose sum is σ = 392148210716352. Its totient is φ = 130716070238782.

The previous prime is 261432140477551. The next prime is 261432140477597. The reversal of 261432140477566 is 665774041234162.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 261432140477566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65358035119390 + ... + 65358035119393.

It is an arithmetic number, because the mean of its divisors is an integer number (98037052679088).

Almost surely, 2^{261432140477566} is an apocalyptic number.

261432140477566 is a deficient number, since it is larger than the sum of its proper divisors (130716070238786).

261432140477566 is a wasteful number, since it uses less digits than its factorization.

261432140477566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130716070238785.

The product of its (nonzero) digits is 40642560, while the sum is 58.

The spelling of 261432140477566 in words is "two hundred sixty-one trillion, four hundred thirty-two billion, one hundred forty million, four hundred seventy-seven thousand, five hundred sixty-six".