20556670219 has 4 divisors (see below), whose sum is σ = 20576964096. Its totient is φ = 20536376344.

The previous prime is 20556670217. The next prime is 20556670223. The reversal of 20556670219 is 91207665502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20556670219 - 2¹ = 20556670217 is a prime.

It is a super-2 number, since 2×20556670219² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20556670217) 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, 10145419 + ... + 10147444.

It is an arithmetic number, because the mean of its divisors is an integer number (5144241024).

Almost surely, 2^20556670219 is an apocalyptic number.

20556670219 is a deficient number, since it is larger than the sum of its proper divisors (20293877).

20556670219 is a wasteful number, since it uses less digits than its factorization.

20556670219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20293876.

The product of its (nonzero) digits is 226800, while the sum is 43.

The spelling of 20556670219 in words is "twenty billion, five hundred fifty-six million, six hundred seventy thousand, two hundred nineteen".