21125036 has 12 divisors (see below), whose sum is σ = 38914680. Its totient is φ = 10006560.

The previous prime is 21125029. The next prime is 21125057. The reversal of 21125036 is 63052112.

It is a junction number, because it is equal to n+sod(n) for n = 21124999 and 21125017.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138905 + ... + 139056.

It is an arithmetic number, because the mean of its divisors is an integer number (3242890).

Almost surely, 2^21125036 is an apocalyptic number.

It is an amenable number.

21125036 is a deficient number, since it is larger than the sum of its proper divisors (17789644).

21125036 is a wasteful number, since it uses less digits than its factorization.

21125036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277984 (or 277982 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 21125036 is about 4596.1979939946. The cubic root of 21125036 is about 276.4388977141.

Adding to 21125036 its reverse (63052112), we get a palindrome (84177148).

The spelling of 21125036 in words is "twenty-one million, one hundred twenty-five thousand, thirty-six".