21125011004 has 12 divisors (see below), whose sum is σ = 36980163528. Its totient is φ = 10559250000.

The previous prime is 21125011003. The next prime is 21125011007. The reversal of 21125011004 is 40011052112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125011001) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 799247 + ... + 825254.

It is an arithmetic number, because the mean of its divisors is an integer number (3081680294).

Almost surely, 2^21125011004 is an apocalyptic number.

It is an amenable number.

21125011004 is a deficient number, since it is larger than the sum of its proper divisors (15855152524).

21125011004 is a wasteful number, since it uses less digits than its factorization.

21125011004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627756 (or 1627754 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 21125011004 its reverse (40011052112), we get a palindrome (61136063116).

The spelling of 21125011004 in words is "twenty-one billion, one hundred twenty-five million, eleven thousand, four".