261620889 has 8 divisors (see below), whose sum is σ = 351575040. Its totient is φ = 173040336.

The previous prime is 261620881. The next prime is 261620921. The reversal of 261620889 is 988026162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261620889 - 2³ = 261620881 is a prime.

It is a super-2 number, since 2×261620889² = 136890979122300642, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261620889.

It is not an unprimeable number, because it can be changed into a prime (261620881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 342954 + ... + 343715.

It is an arithmetic number, because the mean of its divisors is an integer number (43946880).

Almost surely, 2^261620889 is an apocalyptic number.

It is an amenable number.

261620889 is a deficient number, since it is larger than the sum of its proper divisors (89954151).

261620889 is a wasteful number, since it uses less digits than its factorization.

261620889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686799.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 261620889 is about 16174.6990389311. The cubic root of 261620889 is about 639.5740076953.

The spelling of 261620889 in words is "two hundred sixty-one million, six hundred twenty thousand, eight hundred eighty-nine".