125984456821 has 8 divisors (see below), whose sum is σ = 127890451160. Its totient is φ = 124083332352.

The previous prime is 125984456737. The next prime is 125984456833. The reversal of 125984456821 is 128654489521.

It can be written as a sum of positive squares in 4 ways, for example, as 162435025 + 125822021796 = 12745^2 + 354714^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 125984456821 - 2⁷ = 125984456693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125984456881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1165320 + ... + 1268833.

It is an arithmetic number, because the mean of its divisors is an integer number (15986306395).

Almost surely, 2^125984456821 is an apocalyptic number.

It is an amenable number.

125984456821 is a deficient number, since it is larger than the sum of its proper divisors (1905994339).

125984456821 is an equidigital number, since it uses as much as digits as its factorization.

125984456821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2434935.

The product of its digits is 5529600, while the sum is 55.

The spelling of 125984456821 in words is "one hundred twenty-five billion, nine hundred eighty-four million, four hundred fifty-six thousand, eight hundred twenty-one".