21310436 has 12 divisors (see below), whose sum is σ = 42620928. Its totient is φ = 9133032.

The previous prime is 21310433. The next prime is 21310439. The reversal of 21310436 is 63401312.

It is an interprime number because it is at equal distance from previous prime (21310433) and next prime (21310439).

21310436 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21310433) 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, 380516 + ... + 380571.

It is an arithmetic number, because the mean of its divisors is an integer number (3551744).

Almost surely, 2^21310436 is an apocalyptic number.

It is an amenable number.

21310436 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21310436 is a wasteful number, since it uses less digits than its factorization.

21310436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761098 (or 761096 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 21310436 is about 4616.3227790093. The cubic root of 21310436 is about 277.2452484426.

Adding to 21310436 its reverse (63401312), we get a palindrome (84711748).

It can be divided in two parts, 21 and 310436, that multiplied together give a palindrome (6519156).

The spelling of 21310436 in words is "twenty-one million, three hundred ten thousand, four hundred thirty-six".