125400021 has 16 divisors (see below), whose sum is σ = 169905600. Its totient is φ = 82256768.

The previous prime is 125399977. The next prime is 125400029. The reversal of 125400021 is 120004521.

It is a cyclic number.

It is not a de Polignac number, because 125400021 - 2¹¹ = 125397973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125400029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59575 + ... + 61643.

It is an arithmetic number, because the mean of its divisors is an integer number (10619100).

Almost surely, 2^125400021 is an apocalyptic number.

It is an amenable number.

125400021 is a deficient number, since it is larger than the sum of its proper divisors (44505579).

125400021 is a wasteful number, since it uses less digits than its factorization.

125400021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2388.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 125400021 is about 11198.2150809850. The cubic root of 125400021 is about 500.5327933941.

Adding to 125400021 its reverse (120004521), we get a palindrome (245404542).

The spelling of 125400021 in words is "one hundred twenty-five million, four hundred thousand, twenty-one".