20821279478 has 32 divisors (see below), whose sum is σ = 31996166400. Its totient is φ = 10158763104.

The previous prime is 20821279477. The next prime is 20821279481. The reversal of 20821279478 is 87497212802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20821279477) 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, 14388551 + ... + 14389997.

It is an arithmetic number, because the mean of its divisors is an integer number (999880200).

Almost surely, 2^20821279478 is an apocalyptic number.

20821279478 is a deficient number, since it is larger than the sum of its proper divisors (11174886922).

20821279478 is a wasteful number, since it uses less digits than its factorization.

20821279478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2324.

The product of its (nonzero) digits is 903168, while the sum is 50.

The spelling of 20821279478 in words is "twenty billion, eight hundred twenty-one million, two hundred seventy-nine thousand, four hundred seventy-eight".