261641399 has 8 divisors (see below), whose sum is σ = 276086880. Its totient is φ = 247451776.

The previous prime is 261641371. The next prime is 261641423. The reversal of 261641399 is 993146162.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261641399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261641309) 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, 61862 + ... + 65955.

It is an arithmetic number, because the mean of its divisors is an integer number (34510860).

Almost surely, 2^261641399 is an apocalyptic number.

261641399 is a deficient number, since it is larger than the sum of its proper divisors (14445481).

261641399 is a wasteful number, since it uses less digits than its factorization.

261641399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127929.

The product of its digits is 69984, while the sum is 41.

The square root of 261641399 is about 16175.3330413936. Note that the first 3 decimals coincide. The cubic root of 261641399 is about 639.5907205811.

The spelling of 261641399 in words is "two hundred sixty-one million, six hundred forty-one thousand, three hundred ninety-nine".