125165421 has 12 divisors (see below), whose sum is σ = 187029180. Its totient is φ = 80566080.

The previous prime is 125165419. The next prime is 125165429. The reversal of 125165421 is 124561521.

125165421 is a `hidden beast` number, since 1 + 2 + 5 + 1 + 654 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 88623396 + 36542025 = 9414^2 + 6045^2 .

It is not a de Polignac number, because 125165421 - 2¹ = 125165419 is a prime.

It is a super-2 number, since 2×125165421² = 31332765228214482, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125165429) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 239520 + ... + 240041.

It is an arithmetic number, because the mean of its divisors is an integer number (15585765).

Almost surely, 2^125165421 is an apocalyptic number.

It is an amenable number.

125165421 is a deficient number, since it is larger than the sum of its proper divisors (61863759).

125165421 is a wasteful number, since it uses less digits than its factorization.

125165421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479596 (or 479593 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 125165421 is about 11187.7352936151. The cubic root of 125165421 is about 500.2204641102.

The spelling of 125165421 in words is "one hundred twenty-five million, one hundred sixty-five thousand, four hundred twenty-one".