21069545 has 24 divisors (see below), whose sum is σ = 30709824. Its totient is φ = 13591296.

The previous prime is 21069487. The next prime is 21069547. The reversal of 21069545 is 54596012.

It is a happy number.

It is not a de Polignac number, because 21069545 - 2¹⁰ = 21068521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21069547) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9074 + ... + 11156.

It is an arithmetic number, because the mean of its divisors is an integer number (1279576).

Almost surely, 2^21069545 is an apocalyptic number.

It is an amenable number.

21069545 is a deficient number, since it is larger than the sum of its proper divisors (9640279).

21069545 is a wasteful number, since it uses less digits than its factorization.

21069545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2129 (or 2112 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 21069545 is about 4590.1574047085. The cubic root of 21069545 is about 276.1966366352.

The spelling of 21069545 in words is "twenty-one million, sixty-nine thousand, five hundred forty-five".