125821100 has 18 divisors (see below), whose sum is σ = 273032004. Its totient is φ = 50328400.

The previous prime is 125821067. The next prime is 125821117. The reversal of 125821100 is 1128521.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 629006 + ... + 629205.

Almost surely, 2^125821100 is an apocalyptic number.

125821100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

125821100 is an abundant number, since it is smaller than the sum of its proper divisors (147210904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

125821100 is a wasteful number, since it uses less digits than its factorization.

125821100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1258225 (or 1258218 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 125821100 is about 11217.0004903272. Note that the first 3 decimals coincide. The cubic root of 125821100 is about 501.0924115359.

Adding to 125821100 its reverse (1128521), we get a palindrome (126949621).

The spelling of 125821100 in words is "one hundred twenty-five million, eight hundred twenty-one thousand, one hundred".