21310545 has 16 divisors (see below), whose sum is σ = 34163712. Its totient is φ = 11343360.

The previous prime is 21310519. The next prime is 21310561. The reversal of 21310545 is 54501312.

It is not a de Polignac number, because 21310545 - 2⁷ = 21310417 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9040 + ... + 11150.

It is an arithmetic number, because the mean of its divisors is an integer number (2135232).

Almost surely, 2^21310545 is an apocalyptic number.

It is an amenable number.

21310545 is a deficient number, since it is larger than the sum of its proper divisors (12853167).

21310545 is a wasteful number, since it uses less digits than its factorization.

21310545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2792.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21310545 is about 4616.3345849277. The cubic root of 21310545 is about 277.2457211325.

Adding to 21310545 its reverse (54501312), we get a palindrome (75811857).

The spelling of 21310545 in words is "twenty-one million, three hundred ten thousand, five hundred forty-five".