261222642 has 48 divisors (see below), whose sum is σ = 574791360. Its totient is φ = 85730400.

The previous prime is 261222607. The next prime is 261222653. The reversal of 261222642 is 246222162.

It is a happy number.

261222642 is a `hidden beast` number, since 2 + 6 + 12 + 2 + 2 + 642 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 413667 + ... + 414297.

It is an arithmetic number, because the mean of its divisors is an integer number (11974820).

Almost surely, 2^261222642 is an apocalyptic number.

261222642 is an abundant number, since it is smaller than the sum of its proper divisors (313568718).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261222642 is a wasteful number, since it uses less digits than its factorization.

261222642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 959 (or 956 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 261222642 is about 16162.3835494645. The cubic root of 261222642 is about 639.2493167761.

The spelling of 261222642 in words is "two hundred sixty-one million, two hundred twenty-two thousand, six hundred forty-two".