684500120981 has 4 divisors (see below), whose sum is σ = 684507213600. Its totient is φ = 684493028364.

The previous prime is 684500120977. The next prime is 684500120989. The reversal of 684500120981 is 189021005486.

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, and also an emirpimes, since its reverse is a distinct semiprime: 189021005486 = 2 ⋅94510502743.

It is a cyclic number.

It is not a de Polignac number, because 684500120981 - 2² = 684500120977 is a prime.

It is a super-2 number, since 2×684500120981² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684500120989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3399521 + ... + 3595238.

It is an arithmetic number, because the mean of its divisors is an integer number (171126803400).

Almost surely, 2^684500120981 is an apocalyptic number.

It is an amenable number.

684500120981 is a deficient number, since it is larger than the sum of its proper divisors (7092619).

684500120981 is an equidigital number, since it uses as much as digits as its factorization.

684500120981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7092618.

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 684500120981 in words is "six hundred eighty-four billion, five hundred million, one hundred twenty thousand, nine hundred eighty-one".