261505642 has 8 divisors (see below), whose sum is σ = 397224000. Its totient is φ = 129097644.

The previous prime is 261505609. The next prime is 261505681. The reversal of 261505642 is 246505162.

261505642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 827392 + ... + 827707.

It is an arithmetic number, because the mean of its divisors is an integer number (49653000).

Almost surely, 2^261505642 is an apocalyptic number.

261505642 is a deficient number, since it is larger than the sum of its proper divisors (135718358).

261505642 is a wasteful number, since it uses less digits than its factorization.

261505642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1655180.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 261505642 is about 16171.1360763553. The cubic root of 261505642 is about 639.4800806751.

The spelling of 261505642 in words is "two hundred sixty-one million, five hundred five thousand, six hundred forty-two".