1638122961 has 8 divisors (see below), whose sum is σ = 2184593824. Its totient is φ = 1091867040.

The previous prime is 1638122947. The next prime is 1638122977. The reversal of 1638122961 is 1692218361.

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

It is not a de Polignac number, because 1638122961 - 2⁵ = 1638122929 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 (1638122461) 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, 35020 + ... + 67101.

It is an arithmetic number, because the mean of its divisors is an integer number (273074228).

Almost surely, 2^1638122961 is an apocalyptic number.

It is an amenable number.

1638122961 is a deficient number, since it is larger than the sum of its proper divisors (546470863).

1638122961 is a wasteful number, since it uses less digits than its factorization.

1638122961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107471.

The product of its digits is 31104, while the sum is 39.

The square root of 1638122961 is about 40473.7317404758. The cubic root of 1638122961 is about 1178.8236291786.

The spelling of 1638122961 in words is "one billion, six hundred thirty-eight million, one hundred twenty-two thousand, nine hundred sixty-one".