981607359121 has 3 divisors (see below), whose sum is σ = 981608349883. Its totient is φ = 981606368360.

The previous prime is 981607359101. The next prime is 981607359143. The reversal of 981607359121 is 121953706189.

The square root of 981607359121 is 990761.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 121953706189 = 7 ⋅17421958027.

It can be written as a sum of positive squares in only one way, i.e., 759841712721 + 221765646400 = 871689^2 + 470920^2 .

It is not a de Polignac number, because 981607359121 - 2¹⁹ = 981606834833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981607359101) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 495381 + ... + 1486141.

Almost surely, 2^981607359121 is an apocalyptic number.

981607359121 is the 990761-st square number.

981607359121 is the 495381-st centered octagonal number.

It is an amenable number.

981607359121 is a deficient number, since it is larger than the sum of its proper divisors (990762).

981607359121 is an frugal number, since it uses more digits than its factorization.

981607359121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1981522 (or 990761 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 52.

The spelling of 981607359121 in words is "nine hundred eighty-one billion, six hundred seven million, three hundred fifty-nine thousand, one hundred twenty-one".