20508847478 has 16 divisors (see below), whose sum is σ = 35161737120. Its totient is φ = 8788577856.

The previous prime is 20508847477. The next prime is 20508847487. The reversal of 20508847478 is 87474880502.

It is a super-2 number, since 2×20508847478² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20508847477) 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, 69578 + ... + 214146.

It is an arithmetic number, because the mean of its divisors is an integer number (2197608570).

Almost surely, 2^20508847478 is an apocalyptic number.

20508847478 is a deficient number, since it is larger than the sum of its proper divisors (14652889642).

20508847478 is a wasteful number, since it uses less digits than its factorization.

20508847478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154711.

The product of its (nonzero) digits is 4014080, while the sum is 53.

The spelling of 20508847478 in words is "twenty billion, five hundred eight million, eight hundred forty-seven thousand, four hundred seventy-eight".