21088545 has 16 divisors (see below), whose sum is σ = 33799680. Its totient is φ = 11227904.

The previous prime is 21088519. The next prime is 21088549. The reversal of 21088545 is 54588012.

It is a cyclic number.

It is not a de Polignac number, because 21088545 - 2⁵ = 21088513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21088549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13936 + ... + 15374.

It is an arithmetic number, because the mean of its divisors is an integer number (2112480).

Almost surely, 2^21088545 is an apocalyptic number.

It is an amenable number.

21088545 is a deficient number, since it is larger than the sum of its proper divisors (12711135).

21088545 is a wasteful number, since it uses less digits than its factorization.

21088545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2424.

The product of its (nonzero) digits is 12800, while the sum is 33.

The square root of 21088545 is about 4592.2265841311. The cubic root of 21088545 is about 276.2796341475.

The spelling of 21088545 in words is "twenty-one million, eighty-eight thousand, five hundred forty-five".