21540927209 has 8 divisors (see below), whose sum is σ = 22712400480. Its totient is φ = 20373228000.

The previous prime is 21540927203. The next prime is 21540927257. The reversal of 21540927209 is 90272904512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21540927209 - 2⁴ = 21540927193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21540927203) 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, 931787 + ... + 954624.

It is an arithmetic number, because the mean of its divisors is an integer number (2839050060).

Almost surely, 2^21540927209 is an apocalyptic number.

It is an amenable number.

21540927209 is a deficient number, since it is larger than the sum of its proper divisors (1171473271).

21540927209 is a wasteful number, since it uses less digits than its factorization.

21540927209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1887031.

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 21540927209 in words is "twenty-one billion, five hundred forty million, nine hundred twenty-seven thousand, two hundred nine".