261161212 has 12 divisors (see below), whose sum is σ = 492188536. Its totient is φ = 120535920.

The previous prime is 261161177. The next prime is 261161221. The reversal of 261161212 is 212161162.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2511114 + ... + 2511217.

Almost surely, 2^261161212 is an apocalyptic number.

It is an amenable number.

261161212 is a deficient number, since it is larger than the sum of its proper divisors (231027324).

261161212 is a wasteful number, since it uses less digits than its factorization.

261161212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5022348 (or 5022346 counting only the distinct ones).

The product of its digits is 288, while the sum is 22.

The square root of 261161212 is about 16160.4830373352. The cubic root of 261161212 is about 639.1992035038.

Subtracting from 261161212 its reverse (212161162), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 261161212 in words is "two hundred sixty-one million, one hundred sixty-one thousand, two hundred twelve".