261543662 has 4 divisors (see below), whose sum is σ = 392315496. Its totient is φ = 130771830.

The previous prime is 261543619. The next prime is 261543671. The reversal of 261543662 is 266345162.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65385914 + ... + 65385917.

It is an arithmetic number, because the mean of its divisors is an integer number (98078874).

Almost surely, 2^261543662 is an apocalyptic number.

261543662 is a deficient number, since it is larger than the sum of its proper divisors (130771834).

261543662 is a wasteful number, since it uses less digits than its factorization.

261543662 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130771833.

The product of its digits is 51840, while the sum is 35.

The square root of 261543662 is about 16172.3115849281. The cubic root of 261543662 is about 639.5110702608.

The spelling of 261543662 in words is "two hundred sixty-one million, five hundred forty-three thousand, six hundred sixty-two".