21015125412 has 48 divisors (see below), whose sum is σ = 49586402880. Its totient is φ = 6926712832.

The previous prime is 21015125381. The next prime is 21015125419. The reversal of 21015125412 is 21452151012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21015125419) 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 15 ways as a sum of consecutive naturals, for example, 397639 + ... + 447377.

It is an arithmetic number, because the mean of its divisors is an integer number (1033050060).

Almost surely, 2^21015125412 is an apocalyptic number.

It is an amenable number.

21015125412 is an abundant number, since it is smaller than the sum of its proper divisors (28571277468).

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

21015125412 is a wasteful number, since it uses less digits than its factorization.

21015125412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50140 (or 50138 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

Adding to 21015125412 its reverse (21452151012), we get a palindrome (42467276424).

The spelling of 21015125412 in words is "twenty-one billion, fifteen million, one hundred twenty-five thousand, four hundred twelve".