125683721361 has 45 divisors (see below), whose sum is σ = 206427212299. Its totient is φ = 76150681200.

The previous prime is 125683721257. The next prime is 125683721393. The reversal of 125683721361 is 163127386521.

It is a happy number.

The square root of 125683721361 is 354519.

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

125683721361 is a `hidden beast` number, since 1 + 2 + 568 + 3 + 7 + 21 + 3 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 112036808961 + 13646912400 = 334719^2 + 116820^2 .

It is not a de Polignac number, because 125683721361 - 2²³ = 125675332753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (125683721161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 35095591 + ... + 35099171.

Almost surely, 2^125683721361 is an apocalyptic number.

125683721361 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

125683721361 is the 354519-th square number.

125683721361 is the 177260-th centered octagonal number.

It is an amenable number.

125683721361 is a deficient number, since it is larger than the sum of its proper divisors (80743490938).

125683721361 is an frugal number, since it uses more digits than its factorization.

125683721361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7196 (or 3595 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The spelling of 125683721361 in words is "one hundred twenty-five billion, six hundred eighty-three million, seven hundred twenty-one thousand, three hundred sixty-one".