122739610021681 has 27 divisors (see below), whose sum is σ = 124771071114273. Its totient is φ = 120741095834400.

The previous prime is 122739610021657. The next prime is 122739610021709. The reversal of 122739610021681 is 186120016937221.

It is a happy number.

The square root of 122739610021681 is 11078791.

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

It can be written as a sum of positive squares in 4 ways, for example, as 98113799268081 + 24625810753600 = 9905241^2 + 4962440^2 .

It is not a de Polignac number, because 122739610021681 - 2¹¹ = 122739610019633 is a prime.

It is a super-2 number, since 2×122739610021681² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (122739610021601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 256241356800 + ... + 256241357278.

Almost surely, 2^{122739610021681} is an apocalyptic number.

122739610021681 is the 11078791-st square number.

122739610021681 is the 5539396-th centered octagonal number.

It is an amenable number.

122739610021681 is a deficient number, since it is larger than the sum of its proper divisors (2031461092592).

122739610021681 is an frugal number, since it uses more digits than its factorization.

122739610021681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618 (or 809 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 49.

The spelling of 122739610021681 in words is "one hundred twenty-two trillion, seven hundred thirty-nine billion, six hundred ten million, twenty-one thousand, six hundred eighty-one".