125405421 has 4 divisors (see below), whose sum is σ = 167207232. Its totient is φ = 83603612.

The previous prime is 125405419. The next prime is 125405437. The reversal of 125405421 is 124504521.

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: 124504521 = 3 ⋅41501507.

It is a cyclic number.

It is not a de Polignac number, because 125405421 - 2¹ = 125405419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 125405391 and 125405400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125405411) 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, 20900901 + ... + 20900906.

It is an arithmetic number, because the mean of its divisors is an integer number (41801808).

Almost surely, 2^125405421 is an apocalyptic number.

It is an amenable number.

125405421 is a deficient number, since it is larger than the sum of its proper divisors (41801811).

125405421 is an equidigital number, since it uses as much as digits as its factorization.

125405421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41801810.

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 125405421 is about 11198.4561882431. The cubic root of 125405421 is about 500.5399779710.

Adding to 125405421 its reverse (124504521), we get a palindrome (249909942).

The spelling of 125405421 in words is "one hundred twenty-five million, four hundred five thousand, four hundred twenty-one".