661823038121 has 8 divisors (see below), whose sum is σ = 756411048384. Its totient is φ = 567245493360.

The previous prime is 661823038081. The next prime is 661823038171. The reversal of 661823038121 is 121830328166.

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

It is not a de Polignac number, because 661823038121 - 2⁶ = 661823038057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661823038171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2480390 + ... + 2734223.

It is an arithmetic number, because the mean of its divisors is an integer number (94551381048).

Almost surely, 2^661823038121 is an apocalyptic number.

It is an amenable number.

661823038121 is a deficient number, since it is larger than the sum of its proper divisors (94588010263).

661823038121 is a wasteful number, since it uses less digits than its factorization.

661823038121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5232751.

The product of its (nonzero) digits is 82944, while the sum is 41.

The spelling of 661823038121 in words is "six hundred sixty-one billion, eight hundred twenty-three million, thirty-eight thousand, one hundred twenty-one".