21315036 has 24 divisors (see below), whose sum is σ = 52353280. Its totient is φ = 6730992.

The previous prime is 21315031. The next prime is 21315037. The reversal of 21315036 is 63051312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46516 + ... + 46971.

Almost surely, 2^21315036 is an apocalyptic number.

It is an amenable number.

21315036 is an abundant number, since it is smaller than the sum of its proper divisors (31038244).

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

21315036 is a wasteful number, since it uses less digits than its factorization.

21315036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93513 (or 93511 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 21315036 is about 4616.8209841838. The cubic root of 21315036 is about 277.2651954206.

Adding to 21315036 its reverse (63051312), we get a palindrome (84366348).

The spelling of 21315036 in words is "twenty-one million, three hundred fifteen thousand, thirty-six".