261203866 has 48 divisors (see below), whose sum is σ = 501186240. Its totient is φ = 99187200.

The previous prime is 261203851. The next prime is 261203867. The reversal of 261203866 is 668302162.

It is a happy number.

It is a super-2 number, since 2×261203866² = 136454919226691912, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261203867) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 258370 + ... + 259378.

It is an arithmetic number, because the mean of its divisors is an integer number (10441380).

Almost surely, 2^261203866 is an apocalyptic number.

261203866 is a deficient number, since it is larger than the sum of its proper divisors (239982374).

261203866 is a wasteful number, since it uses less digits than its factorization.

261203866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111 (or 1070 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 261203866 is about 16161.8026841067. The cubic root of 261203866 is about 639.2340005530.

The spelling of 261203866 in words is "two hundred sixty-one million, two hundred three thousand, eight hundred sixty-six".