261323628 has 12 divisors (see below), whose sum is σ = 609755160. Its totient is φ = 87107872.

The previous prime is 261323603. The next prime is 261323633. The reversal of 261323628 is 826323162.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

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, 10888473 + ... + 10888496.

It is an arithmetic number, because the mean of its divisors is an integer number (50812930).

Almost surely, 2^261323628 is an apocalyptic number.

It is an amenable number.

261323628 is an abundant number, since it is smaller than the sum of its proper divisors (348431532).

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

261323628 is a wasteful number, since it uses less digits than its factorization.

261323628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21776976 (or 21776974 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 261323628 is about 16165.5073536218. The cubic root of 261323628 is about 639.3316819110.

The spelling of 261323628 in words is "two hundred sixty-one million, three hundred twenty-three thousand, six hundred twenty-eight".