261209356 has 12 divisors (see below), whose sum is σ = 460405960. Its totient is φ = 129664800.

The previous prime is 261209341. The next prime is 261209371. The reversal of 261209356 is 653902162.

It is an interprime number because it is at equal distance from previous prime (261209341) and next prime (261209371).

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, 234345 + ... + 235456.

Almost surely, 2^261209356 is an apocalyptic number.

It is an amenable number.

261209356 is a deficient number, since it is larger than the sum of its proper divisors (199196604).

261209356 is a wasteful number, since it uses less digits than its factorization.

261209356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469944 (or 469942 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 261209356 is about 16161.9725281291. The cubic root of 261209356 is about 639.2384790090.

The spelling of 261209356 in words is "two hundred sixty-one million, two hundred nine thousand, three hundred fifty-six".