1004125021 has 4 divisors (see below), whose sum is σ = 1004521500. Its totient is φ = 1003728544.

The previous prime is 1004124991. The next prime is 1004125027. The reversal of 1004125021 is 1205214001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 400440121 + 603684900 = 20011^2 + 24570^2 .

It is a cyclic number.

It is not a de Polignac number, because 1004125021 - 2¹⁹ = 1003600733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1004124986 and 1004125004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1004125027) 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, 194416 + ... + 199513.

It is an arithmetic number, because the mean of its divisors is an integer number (251130375).

Almost surely, 2^1004125021 is an apocalyptic number.

It is an amenable number.

1004125021 is a deficient number, since it is larger than the sum of its proper divisors (396479).

1004125021 is an equidigital number, since it uses as much as digits as its factorization.

1004125021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396478.

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

The square root of 1004125021 is about 31687.9317879852. The cubic root of 1004125021 is about 1001.3731206766.

Adding to 1004125021 its reverse (1205214001), we get a palindrome (2209339022).

It can be divided in two parts, 1004 and 125021, that added together give a square (126025 = 355²).

The spelling of 1004125021 in words is "one billion, four million, one hundred twenty-five thousand, twenty-one".