125212021 has 16 divisors (see below), whose sum is σ = 145162368. Its totient is φ = 106739200.

The previous prime is 125211973. The next prime is 125212039. The reversal of 125212021 is 120212521.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 125212021 - 2⁷ = 125211893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 125211986 and 125212004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125212051) 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 15 ways as a sum of consecutive naturals, for example, 57081 + ... + 59233.

It is an arithmetic number, because the mean of its divisors is an integer number (9072648).

Almost surely, 2^125212021 is an apocalyptic number.

125212021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

125212021 is a deficient number, since it is larger than the sum of its proper divisors (19950347).

125212021 is a wasteful number, since it uses less digits than its factorization.

125212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2492.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 125212021 is about 11189.8177375684. The cubic root of 125212021 is about 500.2825349846.

Adding to 125212021 its reverse (120212521), we get a palindrome (245424542).

The spelling of 125212021 in words is "one hundred twenty-five million, two hundred twelve thousand, twenty-one".