125820421 has 4 divisors (see below), whose sum is σ = 126041344. Its totient is φ = 125599500.

The previous prime is 125820397. The next prime is 125820467. The reversal of 125820421 is 124028521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 124028521 = 2341 ⋅52981.

It is a cyclic number.

It is not a de Polignac number, because 125820421 - 2⁷ = 125820293 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 (125829421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109605 + ... + 110746.

It is an arithmetic number, because the mean of its divisors is an integer number (31510336).

Almost surely, 2^125820421 is an apocalyptic number.

It is an amenable number.

125820421 is a deficient number, since it is larger than the sum of its proper divisors (220923).

125820421 is an equidigital number, since it uses as much as digits as its factorization.

125820421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220922.

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 125820421 is about 11216.9702237280. The cubic root of 125820421 is about 501.0915101440.

Adding to 125820421 its reverse (124028521), we get a palindrome (249848942).

The spelling of 125820421 in words is "one hundred twenty-five million, eight hundred twenty thousand, four hundred twenty-one".