398611961 has 4 divisors (see below), whose sum is σ = 434849424. Its totient is φ = 362374500.

The previous prime is 398611951. The next prime is 398611987. The reversal of 398611961 is 169116893.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 398611961 - 2¹⁴ = 398595577 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (398611951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18118715 + ... + 18118736.

It is an arithmetic number, because the mean of its divisors is an integer number (108712356).

Almost surely, 2^398611961 is an apocalyptic number.

It is an amenable number.

398611961 is a deficient number, since it is larger than the sum of its proper divisors (36237463).

398611961 is a wasteful number, since it uses less digits than its factorization.

398611961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36237462.

The product of its digits is 69984, while the sum is 44.

The square root of 398611961 is about 19965.2688687130. The cubic root of 398611961 is about 735.9530487781.

The spelling of 398611961 in words is "three hundred ninety-eight million, six hundred eleven thousand, nine hundred sixty-one".