20546671821 has 16 divisors (see below), whose sum is σ = 29679586944. Its totient is φ = 12568388544.

The previous prime is 20546671777. The next prime is 20546671879. The reversal of 20546671821 is 12817664502.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-20546671821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20546670821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1570846 + ... + 1583871.

It is an arithmetic number, because the mean of its divisors is an integer number (1854974184).

Almost surely, 2^20546671821 is an apocalyptic number.

It is an amenable number.

20546671821 is a deficient number, since it is larger than the sum of its proper divisors (9132915123).

20546671821 is a wasteful number, since it uses less digits than its factorization.

20546671821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3154900.

The product of its (nonzero) digits is 161280, while the sum is 42.

The spelling of 20546671821 in words is "twenty billion, five hundred forty-six million, six hundred seventy-one thousand, eight hundred twenty-one".